“The Republican Party is realizing you can’t really hang your hat on it,” said Andrew Taylor, a political science professor at North Carolina State University. “It just isn’t the kind of issue it was.”

The party had been counting on anti-Obamacare sentiment to spur Republican turnout in its quest for a U.S. Senate majority, just as the issue did when Republicans took the House in 2010.

Now, Republicans are seeking a new winning formula for an election less than three months away. Republican pollster Whit Ayres, who has advised U.S. Senate candidates including Marco Rubio of Florida, said the party is pausing to reframe the ads by tying Obamacare to the economy and jobs, the top concerns for most Americans.

“Obamacare will not be the most important issue,” and Republicans will have to “target people very directly” with their messages, said Ayres, who co-wrote a memo this month for outside spending groups such as Crossroads GPS and the American Action Network. The memo came after Ayres tested 57 possible avenues of attack.