Here's a look at the Republican presidential field: Who's in, who's almost in, and who's still waiting for the right moment.
IN THE RACE:
The first major Republican to get into the race, the Texas senator kicked off his campaign March 23 at Liberty University in Lynchburg, Virginia. "I believe in you. I believe in the power of millions of courageous conservatives rising up to re-ignite the promise of America," he said.
The Kentucky senator launched his campaign April 7 in Louisville, where he told a hotel ballroom full of supporters, "I have a message, a message that is loud and clear and does not mince words: We have come to take our country back."
In a speech April 13 in Miami, the senator from Florida called his candidacy for president a way for the country to break free of ideas "stuck in the 20th century." He said, "This election is not just about what laws we are going to pass. It is a generational choice about what kind of country we will be."
The former tech executive chose social media and a nationally broadcast morning TV network show to launch her campaign on May 4, and she quickly went after Democratic front-runner Hillary Rodham Clinton. "I have a lot of admiration for Hillary Clinton, but she clearly is not trustworthy," she said.
The retired pediatric neurosurgeon got into the race the same day as Fiorina with an announcement speech in his native Detroit. "It's time for people to rise up and take the government back. The political class won't like me saying things like that. The political class comes from both parties."
The former Arkansas governor and runner-up in the 2008 GOP presidential primaries kicked off his second White House campaign May 5 in the hometown he shares with former President Bill Clinton — Hope, Arkansas. "Power, money and political influence have left a lot of Americans behind," he said.
The runner-up to Mitt Romney in 2012, Santorum began his return engagement to presidential politics May 27 in his western Pennsylvania hometown of Cabot. "The last race, we changed the debate. This race, with your help and God's grace, we can change this nation," he said.
A former three-term governor of New York, who previously considered presidential campaigns in 2008 and 2012, Pataki got his campaign started on May 28 in Exeter, New Hampshire. "While I saw the horrors of Sept. 11 first hand, in the days, weeks and months that followed, I also saw the strength of America on display. ... I completely reject the idea that we can only come together in adversity."
After all but confirming the week before that he was in, the senior senator from South Carolina made it official Monday with a speech in his hometown of Central, South Carolina, that cast the foreign threats to America in dark terms. "Simply put, radical Islam is running wild. They have more safe havens, more money, more weapons and more capability to strike our homeland than any time since 9/11. They are large, they are rich, and they're entrenched."
The governor of Louisiana took his latest step toward running for president on Wednesday (June 3), when his chief political adviser said Jindal will make a "major announcement" on the 2016 race on June 24 in New Orleans. "Economic collapse is much closer to the door than people realize, our culture is decaying at a rapid rate and our standing in a dangerous world is at an all-time low," Jindal said in May.
The former Texas governor is expected to announce his 2016 presidential bid on Thursday at an airfield outside Dallas, surrounded by prominent veterans — including the widow of Chris Kyle of "American Sniper" fame.
WAITING FOR THEIR MOMENT:
The former Florida governor created a political action committee and super PAC in December and has been raising many millions for the groups expected to support his likely candidacy. Bush has begun visiting early-voting states, has a foreign policy trip to Europe planned for June and is expected to announce his plans shortly after returning.
He says he hasn't decided whether he's running yet, but the New Jersey governor looks an awful lot like a candidate, making frequent trips to early-voting states, delivering a series of policy speeches and raising money for a political action committee and super PAC created by his backers.
The former congressman and current Ohio governor is hinting to donors and voters he's likely to get into the race. His political organization, New Day for America, announced Monday his plans to travel to Iowa later this month.
The real estate mogul and reality television star has launched a presidential exploratory committee and is still debating on whether to get into the race. Never short of self-confidence, he said last month he'd be a force to reckon with in the GOP debates. "Selfishly, the networks would put me on because I get great ratings," Trump said.
The Wisconsin governor says he will announce his decision after signing the state budget, which is expected to pass the Republican-controlled state Legislature in late June. Walker has already created a nonprofit group, Our American Revival, to help promote his expected candidacy, and a super PAC led by his close advisers is also up and running.