The Obama Quote Republicans Can’t Stop Repeating

— -- What a difference 28 words make when they are spoken by the president of the United States.

A few sentences uttered recently by President Obama are fast-becoming the defining talking point of the 2014 election season for GOP candidates across the country.

"I am not on the ballot this fall ... Michelle’s pretty happy about that,” Obama said during a speechto business students at Northwestern University. “But make no mistake, these policies are on the ballot -- every single one of them."

It didn't take long for Republicans to use the president's own words against their Democratic opponents in debates, campaign ads and stump speeches.

Almost immediately after the speech, Senate candidate Thom Tillis, R-N.C., took to Twitter to post a picture of Obama and his opponent Kay Hagan with a link to a blog post on his website titled, "28 words that Democrats really wish President Obama didn’t say today."

By the next morning Pat Roberts, Scott Brown and Mitch McConnell had released new campaign ads featuring the Obama remarks to attack their opponents.

Roberts has been fighting a tough battle for a Kansas Senate seat. His latest ad argues that Obama’s policies such as debt, Obamacare and unemployment are on the ballot – and that a vote for his opponent Greg Orman "is a vote for the Obama agenda."

Arkansas Senate candidate Tom Cotton also used the quote at an event last weekend to link his opponent's voting record to the president's policies.

"He said last week that he may not be on the ballot, but his policies are on the ballot – every single one of them… more debt, higher taxes, Obamacare, a foreign policy of weakness and indecision," Cotton told ABC's Jeff Zeleny. "Here in Arkansas the way you find those policies on the ballot is Mark Pryor – cause Mark Pryor's voted for him 93 percent of the time."

The quote has been a popular go-to line in debates too, and was used by Tillis and Georgia Republican nominee David Perdue in Senate debates this week.

David Axelrod, former senior advisor to the president, said on "Meet the Press" that he would not have included the line if he was still writing the president's speeches.

"It was a mistake," Axelrod said.

When White House Press Secretary Josh Earnest was asked during a briefing if he agreed with Axelrod's assessment he replied, "Well, I guess the short answer is no."

Earnest sought to clarify the president's comments, saying he meant voters have a choice this election between "candidates who are supportive of policies that will benefit the middle class, and candidates who are supportive of policies that will benefit those at the top in the hopes that the benefits will trickle down to the middle class."

ABC's Erin Dooley contributed to this report.