Sen. Bernie Sanders ahead of   President  Obama's State of the Union address before a joint session of Congress on Jan. 12 at the Capitol. (Melina Mara/The Washington Post)

Hillary Clinton's campaign on Tuesday accused rival Sen. Bernie Sanders of following Republican cues to launch attacks on her.

Republicans, including super PACs allied with major candidates, would rather run against Sanders in the fall and are trying to help his insurgent primary challenge to Clinton now, Clinton communications director Jennifer Palmieri said in a statement. Sanders took advantage of the help, she said, by using an attack produced by GOP operative Karl Rove.

“While Senator Sanders tries to make a case on electability based on meaningless polls, Republicans and their super PACs have made clear the candidate they’re actually afraid to face" is Clinton, Palmieri said.

"The Sanders argument falls apart when the GOP spokesman is trying to help him and the Republicans run ads trying to stop Hillary Clinton in the primary. Now he’s taking his cues from them."

American Crossroads, which Rove helped to found, has paid for an ad in Iowa that supports the Sanders claim that Clinton is too cozy with Wall Street, and Sanders has now incorporated the meat of the Rove claims in his stump speech, she said.

Sanders is surging in Iowa, and with fewer than two weeks until voting has erased Clinton's once-formidable lead there. He is ahead, and by some polls far ahead, in New Hampshire. Clinton remains the overall Democratic favorite, but a Sanders victory in Iowa would be an enormous setback. The close race and high stakes have spurred a much more combative stance for each candidate.

Asked about the Clinton campaign statement at a stop in Underwood, Iowa, Sanders was initially dismissive of it.

“Look, in the next two weeks, you’re going to hear a lot of statements from a lot of people," he said.

He then proceeded to rattle off a number of recent national polls and polls from battleground states that showed him beating Trump by a larger margin in a general election than Clinton.

Asked why Republicans are putting out supportive statements about him, Sanders said: "I don’t know that they are putting out supportive statements about me, but I think at the end of the day, we stand a much better chance of defeating Republicans.”

“And it’s not just the polls," Sanders said. “You tell me, which campaign, objectively speaking, is creating the energy and the enthusiasm for a large voter turnout? Everybody knows that it is our campaign.”

He continued with this advice for Clinton: “If I were Secretary Clinton and I had started this campaign as the inevitable, kind of anointed candidate in the Democratic party, and I started 50 points up, and today I’m struggling to win in Iowa, struggling to win in New Hampshire, seeing many polls showing the Sanders campaign is closing the gap, yeah, I would be nervous.”

Palmieri's statement noted other instances when Republicans have sought to bolster Sanders, or in the case of Republican National Committee spokesman Sean Spicer, acknowledge the goal.

During Sunday's Democratic debate, Spicer tweeted "feelthebern" and later did the Twitter version of a forehead slap when Sanders spoke of normalizing relations with Iran.

“Uggggghhh .... phone a friend @berniesanders -- #iran is the number sponsor of terror," Spicer said. "Come on, we are trying to help you."

Spicer later declared Sanders the debate winner, and the RNC blasted out emails citing pundits and others who also credited Sanders with a victory.

Conservative super PAC America Rising  released a web video of news clips critical of Chelsea Clinton’s campaign statements on her mother's behalf, Palmieri added.

John Wagner in Underwood, Iowa, contributed to this report.