Delaying Obamacare's individual mandate to buy health insurance is not on the table, Dan Pfeiffer, a White House senior adviser, said Sunday on NBC's "Meet the Press."

"That will not happen," Pfeiffer said.

The comments come after the House voted Friday to delay the mandate by a decade. The lower chamber has attempted unravel President Obama's signature domestic policy many times before, and the effort is dead on arrival in the Senate.

But the vote came after Democrats lost a tight Florida special election that largely focused on Obamacare.

Rep. David Jolly, R-Fla., defeated his Democratic opponent Alex Sink on Tuesday by a 48.5 percent to 46.6 percent vote in a district Obama narrowly won in 2012.

The results have some Democrats fearing Obamacare might be "political poison," suggested "Meet the Press" host David Gregory.

Pfeiffer, however, maintained the health care policy was a political winner for Democrats during the November midterm elections in which the Senate could flip to Republicans.

"I believe we will keep the Senate," Pfeiffer said.