Americans are so "scared" they're not thinking straight about the upcoming elections, President Obama said over the weekend, as he sought to explain why voters are turning to Republican candidates.

The president, speaking at several rallies and fundraisers as part of his final get-out-the-vote stretch, said Republican candidates are "playing on fear" and suggested voters are falling for it. He said Americans have every reason to be worried, but lamented that "facts" aren't doing his party any good this year.

"People out there are still hurting very badly, and they are still scared. And so part of the reason that our politics seems so tough right now, and facts and science and argument does not seem to be winning the day all the time, is because we're hard-wired not to always think clearly when we're scared," Obama said at a Democratic fundraiser Saturday in Boston. "And the country is scared, and they have good reason to be."

The president is trying to fire up the base and drive up turnout to help minimize the party's expected losses in Congress come Nov. 2. He's scheduled a series of rallies in states he won in the 2008 presidential election and is using them to warn about the direction a Republican-led Congress would take the country.

Obama said Saturday that voters can respond to their "trauma" by either "looking backwards" or looking "forward."

The rhetorical development comes after Obama and the Democratic Party raised alarm about the possibility that foreign contributions could be making their way into the U.S. elections. They suggested groups like the Chamber of Commerce were guilty of this, though they did not offer proof and were quickly rebuffed by the Chamber.

The president touched again on this theme Sunday night at an Ohio rally, where he warned about the influence of "special interests that would profit from the other side's agenda."

"They're fighting back. The Empire is striking back," Obama said to laughter.

At the same rally, where he was joined by first lady Michelle Obama, he described the election as "a contest between our deepest hopes and our deepest fears."

"And the other side is playing on fear," he said. "That's what they do."

But some have accused the White House of turning to cheap tactics to draw voters in the final leg.

Chamber Vice President R. Bruce Josten accused Obama of playing the "fear" card himself in a bid to "change the subject" at a time when the polls are tilted against Democrats.

"We are playing clean. We're abiding by the law. He knows that," Josten told Fox News. "Why they continue to kind of toss up this fear of foreign money can only be to distract and divert attention."