Romney has criticized the White House for calling the attack a spontaneous reaction to an anti-Islamic video on the Internet, then later maintaining it was a terrorist operation possibly tied to al Qaida. The White House says that its statements were based on U.S. intelligence assessments at the times they were made.

The Obama campaign’s other tactic is to portray Romney as a cunning politician whose views change depending on his electoral needs, and is howling at what it sees as Romney’s slow march toward the center in recent days.

In a debate in January during the Republican primary campaign, Romney said that illegal immigrants should “self-deport,” and later said only that he’d look at the issue.

But on Oct. 1 he told The Denver Post that he wouldn’t overturn Obama’s June directive making it easier for certain children of illegal immigrants to stay in this country legally.

Last week, Romney seemed to soften even more, telling Fox News’ Sean Hannity that his assertion that 47 percent of Americans are “victims” overly dependent on government was “completely wrong.”

This week he talked about abortion, telling the Des Moines Register editorial board on Tuesday: “There’s no legislation with regards to abortion that I’m familiar with that would become part of my agenda.”

But he did say he would ban by executive order federally funded international nonprofits from providing abortions in other countries. And the campaign sent a statement to the National Review saying “Governor Romney would of course support legislation aimed at providing greater protections for life.”

“We know the real Mitt Romney will say anything to win,’’ said Stephanie Cutter, Obama’s deputy campaign manager. “Voters shouldn’t be fooled. . . . Women simply cannot trust Mitt Romney.”

Republicans are hoping the Obama script becomes a rerun of 1980, when President Jimmy Carter tried similar tactics against Ronald Reagan.

“You’ll determine whether or not this America will be unified or, if I lose this election, whether Americans might be separated, black from white, Jew from Christian, north from south, rural from urban,” Carter said.

Then the candidates debated.

“When his attempt to demonize Reagan failed – Reagan’s cool, relaxed presidential demeanor in the debate had buried that effort once and for all,” political analysts Jack Germond and Jules Witcover wrote, "Jimmy Carter was politically naked.”