Additionally, when asked to describe the GOP nominating battle in a word or phrase, nearly 70 percent of respondents – including six in 10 independents and even more than half of Republicans – answered with a negative comment.

Some examples of these negative comments from Republicans: “Unenthusiastic,” “discouraged,” “lesser of two evils,” “painful,” “disappointed,” “poor choices,” “concerned,” “underwhelmed,” “uninspiring” and “depressed.

At the outset of this race, it was assumed that Republicans would benefit from an enthusiasm gap in a race against Obama; the lack of interest in the primary contest, though, has thrown that into question.

Why it may be overstated: Because even if their own crop of candidates doesn’t do anything for them, Republican voters still can’t stand Obama. The opportunity to vote against him in the fall may be all the motivation they need.

2. Independents don’t like Mitt

Why it’s a problem: Since the primary season began, Romney negative ratings with independent voters have soared, and his standing among them in head-to-head match-ups with Obama has fallen markedly. Moreover, Romney has failed to win the independent vote in nine of the 13 GOP contests where they’ve been allowed to participate – including the swing states of Ohio (where he lost to Rick Santorum by 6 points among independents), New Hampshire, Nevada and Iowa.

This doesn’t compare well with the example of Obama, who tended to win the independent vote in his 2008 nomination battle with Hillary Clinton. For instance, when Obama lost Ohio to her, he still carried independents by 2 points, allowing his campaign to argue that he was better positioned to expand the party’s base in the fall.

But this year’s GOP process has forced Romney to live in fear of a party base that is wildly out of step with general election swing voters, and the effect could be showing. “He continues to lose among independent voters,” Axelrod said on Wednesday, “and that’s going to become increasingly so as he tacks further to the right.”

Why it may be overstated: In some states, like Iowa, New Hampshire and Nevada, Romney only lost the independent vote because an outsize chunk of it went to Ron Paul, something that probably spoke more to the large, loyal and unique following the libertarian congressman enjoys among non-Republican voters. And we don’t know how many “independents” in more recent contests are functional Democrats taking advantage of the lack of action on their side and trying to cause mischief in the GOP race. Plus, the ultimate, if unspoken, hope of any Republican nominee this year will be that the economy takes a turn for the worse before the election; if that happens, then swing voters, even if they are cool to him now, will be strongly inclined to give Romney a second look.

3. The youth vote

Why it’s a problem: Four years ago, Obama enjoyed a massive advantage – nearly 40 points – among voters between the ages of 18 and 29, a much wider gap than had been seen in the 2004 and 2000 elections. Plus, while young voters’ overall share of the ’08 electorate didn’t rise (because participation increased across the board), the turnout rate among them did tick up to 46 percent. On Wednesday’s call, Messina played up efforts by the Obama campaign to recapture this enthusiasm this year. Meanwhile, participation in the GOP primaries has skewed older, and there’s little evidence that the party and its candidates are resonating with young voters.

Why it may be overstated: It’s probably impossible for Obama to enjoy the same advantage he did four years ago, since he’ll be running this year on a record that has attracted mixed reviews even from many of his supporters. And in a recent piece for the New Republic, demographer Cheryl Russell argued that participation among 18-to-29-year-olds will drop this year because of the struggling economy, which has exacerbated un- and underemployment among young people and further delayed their embrace of marriage and home ownership — “adult commitments that give people a stake in society.”

4. Alienation of Latinos

Why it’s a problem: America’s fastest-growing minority group holds increasing sway in a number of swing states, particularly in the West – so much that Obama’s campaign sees an opportunity to make up for possible Rust Belt losses by rallying Latinos in Colorado, New Mexico, Nevada and maybe even Arizona.

This optimism stems from the GOP’s poisonous image among Hispanic voters. A Fox News Latino poll this week shows Obama leading Romney by 56 points, 70 to 14 percent, among Latinos, while an ABC News/Univision survey finds that a combined 72 percent of Latinos believe the GOP either doesn’t care about reaching out to them or is hostile to them. This, in turn, is probably the result of the GOP base’s anti-immigration absolutism, which has compelled the party’s leaders and presidential candidates — Romney, in particular – to take hard-line positions. As Greg Sargent pointed out Wednesday, though, the new ABC/Univision survey also provides evidence that Latinos tend to agree with Democrats’ broader economic message.

Why it may be overstated: Obama’s advantage over Romney in the Fox News Latino survey is massive, but he also took 67 percent of the Latino vote in 2008. Republicans would ideally like to chip away at this (George W. Bush held John Kerry to just 53 percent in 2004), but it’s long been assumed that Obama would enjoy a significant advantage here in ’12. At the same time, Obama’s record as president and his immigration policies have taken their toll on his image with Latinos; 53 percent of them say they are less enthusiastic about him now than when he took office, and a combined 46 percent say Democrats either don’t care about reaching out to them or are hostile to them.

5. Blue-collar resistance to Romney

Why it’s a problem: Obama didn’t win white working-class voters in ’08, but he did better among them than Kerry and Gore. But in 2010, they broke hard for the GOP, a major reason the midterm was so bloody for Democrats. Especially in light of their woes with Latino voters, it’s essential for Republicans to perform at or near that ’10 level with blue-collar whites if they’re going to unseat Obama this fall.

Against this backdrop, the demographic profile of Romney’s primary season army is startling. In state after state, there’s been a direct relationship between GOP voters’ income level and their enthusiasm for him. This was most dramatically illustrated on Tuesday night in Ohio, where Romney lost voters making between $50,000 and $100,000 by 11 points and those making between $30,000 and $50,000 by 6 – but made up for it with a blockbuster showing among those making between $100,000 and $200,000 (a 10-point win) and those making over $200,000 (a 29-point win). Because turnout among wealthy voters actually rose in Ohio from 2008, it could be argued that Romney’s 1-point statewide victory was keyed by the rich.

In 2008, Mike Huckabee famously said that Romney reminds blue-collar voters of “the guy who fired you.” If that image is at the core of his struggles with working- and middle-class Republican voters, it could easily spill over to working- and middle-class swing voters in the fall.

Why it may be overstated: The resistance of blue-collar Republican voters to Romney may be more ideological than we realize. That is, it may be that lower-income, less-educated GOP primary voters just tend to be more conservative and more religious, and that their objections to Romney stem more from his moderate image, and maybe even his Mormonism. If this is the case, than the effect may not extend as much to the general election audience.