One House Republican who spoke to The Hill on background said he’s been encouraged by his colleagues’ support of Rubio.

“I recognize the fact that if Rubio is our nominee, we’ve got a chance to really grow our vote share of Republicans,” said a GOP lawmaker who will not make a formal endorsement in the primary. “If Trump is our nominee, it will shrink the number. So I think it’s good for our party if Rubio is the nominee.

“When you have conservatives like Chaffetz and Gowdy get on board with Rubio, it tells me this internal thought process we’re having … we’re coming to the right conclusion that we need the most conservative, electable candidate.”

The endorsements could also help Rubio with the GOP’s donor class, says Republican strategist and former senior congressional aide Ron Bonjean.