Sen. John Thune (R-S.D.), the third-highest ranking Republican in the Senate, said he expects the Gang of Eight immigration bill will gain more than 60 votes, enough to avoid a filibuster from opponents.
"I think there's a very real possibility that that they'll have 60 — beyond 60, north of 60 — in order to get on the bill and then probably ultimately to pass it. The question is, can change be made in order to attract more people to it and make it a larger number?" said Thune on MSNBC’s “Mitchell Reports.”
"I'm going to make that judgment after it moves across the floor and we get an opportunity through the amendment process to see how the bill gets changed, how it might get improved," he said.
Thune's comments come a day after Sen. Kelly Ayotte (R-N.H.) endorsed the Senate immigration bill.
The bill would legalize the status of the 11 million immigrants living in the country illegally, strengthen border security measures and create new guest-worker and high-tech visa programs.
But conservative Republicans see the plan as “amnesty” and want more action on strengthening the border.
Sen. Marco Rubio (R-Fla.), one of the bill’s co-authors, said last week he would vote against it without more border security. Rubio, a Tea Party favorite, is seen as a key figure in winning additional conservative support to avoid a filibuster.
On Sunday, Sen. Mike Lee (R-Utah), urged lawmakers to oppose the bill, linking it to the Obama administration's healthcare law.
"It is big government dysfunction. It is an immigration ObamaCare," Lee said. "All advocates of true immigration reform — on the left and the right — should oppose it."
The Senate is expected to vote on a motion to proceed to the immigration bill on Tuesday afternoon.