Cruz, a freshman senator from Texas running for president, and right-leaning groups see huge dangers in having a session after the November elections, which they think could be used to move legislation backed by President Obama or even to confirm his Supreme Court nominee.

Indeed, business groups disappointed with the glacial pace in Congress this year see the lame duck as virtually the only chance of moving some of their most prized bills, including legislation implementing the Trans-Pacific Partnership trade deal.

“Passage of the Trans-Pacific Partnership is the No. 1 fear of grassroots conservatives and Tea Party voters with regard to a lame-duck session,” said a senior GOP aide familiar with the movement.

“I’m guessing K Street will want a massive lame-duck session unless Hillary Clinton wins the White House. They know they better get what they can while Barrack Obama, Paul Ryan and Mitch McConnell are in charge,” the aide said, referring to D.C.’s lobbying community.