TAMPA, Fla. (AP) — Mutual admiration was the rule for Democratic Sen. Bill Nelson’s listening session at the University of South Florida.

School provost Ralph Wilcox introduced the two-term senator as a “steadfast advocate for all Floridians.” Nelson, a former astronaut, flattered the more than two dozen students present, saying they had a keen sense about people running for elected office. “You guys can usually smell out folks. You can spot a phony,” he said.

Nelson collected their personal stories about the unbearable weight of student loans for a Senate speech days later on the need to keep the interest rate low. At the conclusion of the hour-plus session, he posed for photos with students.

Don’t go looking for compliments and congeniality in the Republican primary to decide Nelson’s election-year challenger. It’s one of the meanest races in the country.

George LeMieux calls rival Connie Mack a congressional no-show, claiming that the four-term House member spends more time in California with his wife, Rep. Mary Bono Mack, than either in Florida or on Capitol Hill. A devastating web video from LeMieux portrays Mack as Hollywood bad boy Charlie Sheen, highlighting years-old bar fights and Mack’s previous experience as an events coordinator for Hooters.

Privately, top Republicans in the state bemoan their choices and the GOP candidates’ anemic fundraising.

It wasn’t supposed to be like this in Florida or Pennsylvania or Michigan, three presidential battleground states. Republicans romped in all three in 2010, grabbing governorships, seizing majority control of state legislatures, and winning House and Senate seats. The three Democratic senators facing re-election in 2012 — Nelson, Bob Casey of Pennsylvania and Debbie Stabenow of Michigan — were certain to face top GOP recruits and strong political headwinds.

Now, roughly five months to Election Day, the three states look like missed opportunities for the GOP.

In Pennsylvania, Republican Gov. Tom Corbett’s choice to challenge Casey finished an embarrassing third in the April primary. The GOP nominee is Tom Smith, who made a fortune in the coal mining business but lacks the name recognition of Casey, the son of a popular former governor.

In Michigan, former Rep. Pete Hoekstra, who finished second in the 2010 GOP primary for governor, stumbled in January with a controversial ad in which a young Asian woman spoke in broken English about China taking U.S. jobs. He faces a challenge from Clark Durant, who has the support of top Republicans Spencer Abraham and Saul Anuzis in a likely five-man primary on Aug. 7. Abraham represented Michigan in the U.S. Senate until he was ousted by Stabenow in the 2000 election, while Anuzis is running for Republican National Committee chairman.

The GOP envisions a road to a Senate majority — it needs a net gain of four seats to win control — but at this stage, Pennsylvania, Michigan and Florida aren’t prime real estate.

“The environment can change in pretty short order,” Casey said in an interview, recalling his father’s success in 1990 and President Bill Clinton’s in 1992, followed by Republican wins in 1994 and 1998. “We don’t know what 2012 will be. We don’t know whether it will be a dramatic departure from 2010 or not.”

Christopher Borick, assistant professor of political science at Muhlenberg College, describes Casey as the prohibitive favorite based on his solid approval ratings, crossover appeal with Republicans and independents and his willingness to challenge President Barack Obama on several issues, most notably the requirement — later amended — that religious schools and hospitals provide insurance for free birth control to their employees.

Votes in Pennsylvania for Romney and Casey “won’t be uncommon,” Borick said.

Casey has $5.3 million cash on hand to Smith’s $2 million, though the senator said “it’s always a struggle when you’re running against someone who can take out a pen” and write a personal check. Stabenow, who recently completed work on a five-year farm bill as chairwoman of the Senate Agriculture Committee, has close to $7 million cash on hand, while Hoekstra and Durant have about $1.5 million apiece.

In Florida, Republicans describe Nelson as one of the luckiest politicians, with support they insist is a mile wide but only an inch deep. They point to his less-than-formidable opponents in past elections, former Rep. Bill McCollum and divisive 2000 recount figure Katherine Harris, whom he beat 60-38 percent in 2006.

Mack, in the first rush of fundraising, emerged with just $1.38 million cash on hand at the end of March, according to Federal Election Commission reports. LeMieux had $1.19 million. By comparison, Nelson reported $9.54 million cash on hand to run in a state with 10 expensive media markets.

This spring, Republicans, including freshman Sen. Marco Rubio, had talked up the candidacy of Florida’s chief financial officer, Jeff Atwater, but he decided against running.

LeMieux claims Mack — great-grandson of baseball Hall of Fame manager Connie Mack and son of the former senator — is in Washington on name recognition only.

Mack “doesn’t have the competency or character to be U.S. senator. If his name were Connie Smith, he wouldn’t have been elected to anything,” LeMieux said in an interview. LeMieux, who served as interim senator, added, “It’s hard to ask for a promotion when you’re not showing up for work.”

Mack has the backing of likely Republican presidential nominee Mitt Romney and is considered the front-runner in the Aug. 14 primary. He’s answering LeMieux’s attacks with his own assault.

Seizing on published reports last week, Mack’s campaign called for a Justice Department investigation into allegations that LeMieux pressured then-Gov. Charlie Crist to appoint him to the Senate for the remaining 16 months of Republican Mel Martinez’s term in 2009. The newspaper reports suggested the two had a quid pro quo, with LeMieux backing Crist’s unsuccessful Senate bid in 2010.

Mack shrugs off LeMieux’s criticism as “juvenile” and insists that the former senator should be ashamed.

“George LeMieux is fixated on making a joke of his own campaign. We’re fine to let him do that,” Mack said in an interview, arguing that he’s more focused on addressing the nation’s problems.

Stepping into this scorched earth race is former Rep. Dave Weldon, who launched his late bid arguing that none of the candidates, including businessman Mike McCalister, has won over conservatives.

The races are certain to tighten as the November election closes in, especially with a divided electorate, outside money in the millions, and Obama and Romney spending millions more.

“Keep your eye on Florida because it is ground zero,” Nelson said in an interview, pointing out that Florida’s 29 electoral votes make it the biggest prize among swing states.

The U.S. Chamber of Commerce recently spent $2 million on an ad criticizing Nelson for his support for Obama’s health care law.

“Obamacare will be a nightmare for seniors,” the ad says. “Did Bill Nelson consider the consequences when he cast the deciding vote for Obamacare?”

Among several locations, the ads ran in Tallahassee and Panama City, part of the Florida Panhandle in the northwestern part of the state. The choice was intentional as state Republicans and Democrats say the folksy Nelson runs stronger in the Panhandle than most Democrats, including Obama.

Mack is already trying to undercut that support, referring to Obama and Nelson as “two lock-step liberals who are joined at the hip.”

Nelson will benefit, though, from the Obama campaign’s strong organization in the state, said Orlando Mayor Buddy Dyer, a Democrat who recently was re-elected.

“They’ve been at it for a year already in central Florida. … They have a very visible presence,” Dyer said.

WASHINGTON (AP) — The Pentagon’s investment in green energy requires too much green paper for some in Congress.

A sharply divided Senate Armed Services Committee voted this week to prohibit the military from spending money on alternative fuels if the cost exceeds traditional fossil fuels such as coal, natural gas and oil. The move underscores congressional concern about the greater expense of clean energy sources such as biofuels as the Pentagon wrestles with smaller budgets.

The committee’s action came while crafting a defense budget for next year. It also voted to block construction of a biofuels refinery or any other facility to refine biofuels.

Both efforts passed on 13-12 votes that were disclosed Friday.

The Pentagon is pushing for $1.4 billion for investments in clean energy, including hybrid electric drives for ships and more efficient engines.

WASHINGTON (AP) — The Senate Ethics committee has admonished Republican Sen. Tom Coburn over his involvement with a staffer to former Sen. John Ensign.

In a letter released Friday, the six-member panel said Coburn’s communications and actions with Doug Hampton were improper conduct and warranted a public letter of qualified admonition. The committee said contact between the two violated the Senate rule barring contact on legislative matters within the first year of a staffer’s departure.

The panel said the letter closes the matter.

Ensign was having an affair with Hampton’s wife. In 2008, Hampton received a $96,000 gift from Ensign’s parents, and an earlier Ethics Committee report cast Coburn as participating in subsequent, unsuccessful negotiations in May 2009 over a far larger amount.

Ensign, a Nevada Republican, quit May 3, 2011.

WASHINGTON (AP) — A Senate panel on Thursday rejected the Pentagon’s proposed cuts in personnel and equipment for the Air National Guard as it completed a far-reaching, $631 billion defense budget for next year.

Republicans and Democrats on the Armed Services Committee unanimously backed the budget, which called for the same amount of money President Barack Obama had proposed for the military earlier this year. The total is $4 billion less than the House-passed bill, and House-Senate negotiators will have to work out the difference.

WASHINGTON (AP) — A Senate panel expressed its outrage over the conviction of a Pakistani doctor who helped the U.S. get Osama bin Laden by slashing aid by $33 million — $1 million for every year of the doctor’s 33-year sentence.

The Appropriations Committee approved the amendment 30-0 on Thursday as Republicans and Democrats widely criticized Pakistan’s conviction of Shakil Afridi for high treason a day earlier. Afridi ran a vaccination program for the CIA to collect DNA and verify bin Laden’s presence at the compound in the town of Abbottabad where U.S. commandos killed the al-Qaida leader in May 2011.

The United States has called for Afridi to be released.

The vote came on a $52 billion foreign aid budget for next year.

WASHINGTON (AP) — The nation’s top military leader says U.S. approval of a long-spurned high seas treaty would strengthen American naval power.

In prepared testimony Wednesday, Army Gen. Martin Dempsey told Congress that the U.N. Convention on the Law of the Sea would ensure navigational rights and freedoms needed to project and sustain U.S. military forces.

In a rare step underscoring Obama administration support for the treaty, Dempsey was testifying along with Defense Secretary Leon Panetta and Secretary of State Hillary Rodham Clinton.

The treaty was concluded in 1982 and has been in force since 1994. The U.S. is the only major nation that has refused to sign the treaty, which has been endorsed by 161 countries and the European Union.

Members of the tea party fear the treaty will undermine U.S. sovereignty.