Big-dollar donations from outside groups and the national party dried up for Representative Todd Akin after his heinous remarks about “legitimate rape.” But now, with only days before the election, the faucet has suddenly been turned back on. And thanks to our opaque campaign finance system, we don’t know who is behind the late money—and it seems quite likely the groups who publicly swore off supporting Akin have reversed their stance.

Yesterday, a group called Now or Never Political Action Committee announced it would dump $800,000 into the race on behalf of Akin, while Akin’s campaign and the Missouri Republican Party announced a $700,000 ad-buy for the final stretch.

This additional $1.5 million is truly notable because it dwarfs the support Akin has seen so far—as we noted recently, the outside groups that stood by Akin have been doing so with much smaller contributions. Jim DeMint’s Senate Conservatives Fund has spent $114,773 on an e-mail campaign and also raised $390,000 from members, which it donated to Akin’s campaign, according to Matt Hoskins, the group’s executive director.* Freedom’s Defense Fund, the only Super PAC to really get behind Akin since his remarks, kicked in $201,562 to date. So this is a significant late push.

At the surface level, the late push seems rather innocuous—that, indeed, the national party and big outside groups like Crossroads GPS are still sticking by their word not to support Akin.

But a closer look reveals that these very groups are probably coming to Akin’s defense through back doors. Reporters quickly noted that Akin’s campaign and the state GOP probably don’t have the money on hand to make a $700,000 ad buy, since combined they declared about that much money at the October 17 FEC filing deadline, and have been spending quite a bit since.

That means they either raised a heck of a lot of money in two weeks—possible, but unlikely, and not consistent with what the Akin campaign has been saying it raised—or, they are getting support from the national party. Legally, only national committees can lend that support to Akin’s campaign and the state party.

The Republican National Committee has denied it, leaving the NRSC as the only suspect—and it suspiciously refuses to comment about whether it is indeed the source of the money. (Remember, the NRSC floated the idea of supporting Akin in late September, but NRSC chairman Senator John Cornyn then went on the record and ruled it out again).

So it’s an overwhelming likelihood that the NRSC has gone back on its word. Is the same true of Crossroads GPS and other big-dollar conservative groups that swore off Akin? Examining Now or Never PAC’s finances suggests yes.

Since it is a Super PAC, Now or Never does actually have to disclose donors. The group, based in Kansas City, Missouri, and run by a local lawyer, mainly has “small” donors who contribute $250,000 or less. But it late September it received two contributions totaling nearly $2 million from a group called Americans for Limited Government, which appears to be supporting a bulk of Now or Never’s activities.

Americans for Limited Government is a 501(c)(4) “social welfare” group that does not have to disclose donors. We do know that in the past, it has received well over $4 million from the Center to Protect Patients Rights, another massively-funded 501(c)(4) about which we know very little—though it does appear to have some connection to the Koch brothers.

In short, the entire operation is a black box. We ultimately have no idea where the Now or Never PAC money now supporting Akin came from. Did the same donors that normally support Crossroads GPS instead give to Americans for Limited Government? Perhaps, but in any case, this seems like an obvious back-door way for super-wealthy conservatives to fund Akin when they had previously claimed they would not.

Still—if you are worried that the race will suddenly tilt to Akin, don’t be. This is a lot more money than Akin has seen, but still very small in comparison to what McCaskill and her allies have been spending.

A $700,000 push from the NRSC is nice, but in October alone the Democratic Senatorial Campaign Committee spend $2,580,231 on the race, and is likely to still match or exceed Akin’s final push. The additional $800,000 from Now or Never PAC is surely helpful, but there are the myriad liberal groups like Planned Parenthood, American Bridge, Majority PAC, NARAL and others still chipping in to back McCaskill.

Moreover, a late $1.5 million push from groups supporting Akin—which, again, is likely to at least be matched—probably can’t move the needle far enough for Akin. RealClearPolitics, which has a conservative trend in its polling averages, has McCaskill up by 5. Nate Silver gives her just over a 90 percent chance of winning.

* This story has been updated to reflect the money raised by SCF for Akin. 

Tom Engelhardt wrote about money’s supersizing effect on American politics.