It’s official—at 5 pm yesterday, Representative Todd Akin’s name was cemented on the ballot in Missouri for this fall’s Senate race. During a defiant press conference Tuesday afternoon in which he compared himself to Harry Truman, Akin said he would abide by the Republican primary results. “The decision was made by the voters of the state of Missouri,” he said.

Now that Akin is the GOP’s only chance to pick up a crucial Senate seat in Missouri, will the party and it’s major outside groups—Crossroads GPS, the Club for Growth, the US Chamber of Commerce and others—return to Akin’s side, as many cynics predicted a month ago?

Each of those groups reaffirmed yesterday that they will not back Akin, and I believe them, for several reasons. The first is a matter of branding. The national party and the major outside organizations are going to be spending heavily in many crucial races across the country. Democrats are already eager to tie Akin to other congressional candidates and the GOP presidential ticket, and a reversal by the NRSC and the outside players would provide a common denominator between Akin and other candidates. GOP Senate hopefuls like Josh Mandel and Connie Mack surely don’t want their opponents saying that the same groups attacking them are also trying to get Todd Akin into the Senate.

The second is a matter of strategy—Akin probably can’t win. Some polls show a tied contest, but McCaskill and her allies have barely laid a glove on Akin over his “legitimate rape” remark and other extreme positions on the premise that burying Akin right away might chase him from the race while he could still get off the ballot.

Now, with the deadline passed, the knives are out: literally within an hour of the withdrawal deadline, McCaskill released a television ad blasting Akin for the rape comments and asking “What will he say next?” National Democrats immediately unleashed an oppo-dump of crazy Akin comments, like when he insisted the National Defense Authorization Act legalized bestiality.

Republican officials told reporters this week point-blank they did not believe the polls would hold after McCaskill and her allies released the post–September 25 barrage of attacks, and they’re probably right. Whether the NRSC and Karl Rove would back Akin if they believed he had a chance to win is an interesting question—but a largely academic one.

But just because Akin won’t be getting their support, it doesn’t mean he’s totally on his own—he’s working hard to cobble together a hard-right, grassroots coalition of funders to support his campaign.

The powerful Senate Conservatives Fund, run by Senator Jim DeMint, announced today it will raise money for Akin, and Rick Santorum will be helping that effort. SCF was instrumental in getting Tea Party Senators Marco Rubio, Rand Paul, Ron Johnson, Mike Lee and Pat Toomey elected in 2010—though, notably, it also helped cost the GOP seats in Alaska, Delaware, and Nevada by juicing up candidates that were too extreme.

Other hard-right outside groups are pitching in too. Freedom’s Defense Fund, run by noted conspiracy crank Jerome Corsi (one of the leaders of the birther movement in 2008, who has more recently taken to alleging that Obama is gay) announced Tuesday it will be buying $250,000 in advertisements for Akin. The group spent $3 million in 2010, and has a history of running inflammatory ads—like the one against Obama in 2008 accusing him of having “campaigned” for a “communist” Kenyan leader who “spread fundamental Islamic law” while “the Christian majority is under attack.” (Note, however, the group appears to be cash-strapped right now, to say the least).

Akin’s campaign is also launching on a small-dollar grassroots fundraising drive, targeting his base of anti-abortion activists and Christian conservatives. That has already raised $600,000. And at least some Republicans will help him raise money—Newt Gingrich is already doing it, and aside from Santorum and DeMint, J.C. Watts and Rand Paul are reportedly going to pitch in, too.

His home-state allies are coming around, too. Senator Roy Blunt announced his support Tuesday, as did the state Republican Party and the Missouri Farm Bureau, which never actually abandoned Akin—it was the only outside group to run ads for Akin since the “legitimate rape” comments, according to FEC records.

The question is whether this will be enough. Outside groups were expected to spend $15 million on the Republican candidate in Missouri, and it’s extremely hard to envision Akin making up for that loss—meaning Missouri will likely be the only contested Senate race in the country where outside spending runs in favor of the Democrat.

There’s another pitfall, too. By leaning harder on right-wing backers for money, he’s only appearing more extreme. (Akin already had to reverse his pro-earmark position to appease DeMint). This is exactly how McCaskill wants voters to see him.

UPDATE: Well, shame on me for giving the NRSC too much credit. Their executive director just released a statement saying: “There is no question that for Missourians who believe we need to stop the reckless Washington spending, rein-in the role of government in people’s lives, and finally focus on growing jobs in this country that Todd Akin is a far more preferable candidate than liberal Senator Claire McCaskill. As with every Republican Senate candidate, we hope Todd Akin wins in November and we will continue to monitor this race closely in the days ahead.” So they may be getting in this thing after all.

As I said earlier, though—this makes it even easier for Democratic Senate candidates to point out that their opponent is being propped up by the same outfit trying to put Todd Akin in the Senate. 

For more on Missouri’s high-profile senate race, read George Zornick’s on the Akin-McCaskill debate last week.