First Thoughts: Why isn't this GOP race over? Why isn't this GOP race over?... Three answers: 1) Romney's getting penalized for the competition he's facing... 2) He's struggling in the South, which just happens to be the battleground for next week... 3) He hasn't fixed his message problem (and a message about math and inevitability probably isn't going to do the trick) ... Obama: The Documentary... And another leadership challenge for Boehner. Why isn't this GOP race over? If you're Mitt Romney, you have to feel pretty frustrated. Political observers (including your authors here) told him he had to win his native state of Michigan, and he won Michigan. They told him he had to win Ohio, and he won there, too. And they set the bar at him obtaining a majority or a near-majority of delegates on Super Tuesday, and he achieved that as well. So why isn't this race over? One possible answer: He's getting penalized in the media and among Republicans for the competition he's facing. It would be one thing if Romney were eking out narrow victories against Rick Perry or Tim Pawlenty, candidates with (at the time they were running) a serious campaign infrastructure and money or the potential for it. But it's another thing to narrowly win against candidates who don't have a true organization, who aren't well funded, and who don't have a bustling campaign headquarters. Romney, of course, doesn't get to pick his opposition, and all he can do is continue to win. But he is certainly losing style points by barely beating Santorum in states like Michigan and Ohio -- akin, as we've said before, to a top-ranked college football team winning a squeaker against an unranked opponent. Goin" South: Here's another reason why the race isn't over: the South. There is no other region in the country that better represents today's Republican Party than the South, with its deep conservatism, its ardent belief in states" rights, and all of its evangelical voters. And there's no other region in the country where Mitt Romney has struggled more -- in 2012 and also in 2008 -- than there. He has failed to win over his party's nerve center and frankly, it's logical that Republican pooh-bahs are sitting on the sidelines until Romney proves he can win over some of these folks. That said, this deep-red region won't be a problem for him in a general election (with the exception of New South states like North Carolina and Virginia). And after next week's primaries in Alabama and Mississippi -- where all the candidates, including Romney, are campaigning today -- the GOP contest moves elsewhere. But there are still plenty of southern primaries after March 13, where Santorum (or Gingrich) might be favored: Louisiana (March 24), North Carolina (May 8), West Virginia (May 8), Arkansas (May 22), Kentucky (May 22), and Texas (May 29). A message of math and inevitability isn't going to convince conservatives: There is a final reason why this GOP race isn't over yet: Romney still hasn't fixed his message problem. He hasn't explained why (outside of his business experience) he's the person who should carry the conservative flag in November's general election. And this campaign's latest message -- inevitability and math -- isn't going to do the trick. Romney has to give conservatives something to rally around other than delegate counts. And the campaign has to walk this line VERY carefully. The last time the words "Romney" and "inevitable nominee" were used together consistently, candidacies like Cain, Santorum and Gingrich rose from the ashes. The campaign ought to let others make the math argument (it might come across as more credible) and instead fix their message problem. On the trail, per NBC's Adam Perez: Romney stumps in Mississippi, holding an event in Pascagoula (Trent Lott's hometown) ... Gingrich is also in the state, attending rallies in Jackson, Tupelo, and Southaven... And Santorum hits Alabama, visiting Huntsville, Pelham, and Mobile. Obama: The Documentary: In other news today, the Obama campaign has released a trailer of a new documentary -- by award-winning director Davis Guggenheim and narrated by Tom Hanks -- about Obama's first three years in office. Meanwhile, the RNC is out with a document hit on David Axelrod's criticism of Mitt Romney that he didn't stand up to Rush Limbaugh's attack on that female Georgetown Law student. "If you can't stand up to the most strident voices in your party, how are you going to stand up to Ahmadinejad?" Axelrod asked. Well, the RNC's research document asks: "If you can't stand up to the environmentalists in your party" - on the Keystone pipeline - "how are you going to stand up to Ahmadinejad." Also: "If you can't stand up to Nancy Pelosi and Harry Reid" - on the stimulus - "how are you going to stand up to Ahmadinejad?" Another leadership challenge for Boehner: The Hill reports on House Speaker John Boehner trying to get his GOP caucus to support a House transportation bill. "During a closed-door conference meeting Wednesday he implored conservatives to support five-year, $260 billion transportation legislation that has been stalled for weeks, warning them that if they failed to do so, they have to swallow the $109 billion Senate bill or "something that looks just like it." According to a source in the room, Boehner said, "You don't like that? I don't like it either. Why would any of us like it?"" The stakes aren't as big as last summer's debt-ceiling showdown, but this transportation is another opportunity to show 1) that he can lead his caucus, and 2) that the GOP can govern. Countdown to Alabama, Hawaii, and Mississippi: 5 days Countdown to Election Day: 243 days