Congressional Republicans say the opposition from their activist base to the Senate plan is only growing, making it easier for GOP senators to oppose the Senate bill — particularly if the border security provisions remain largely unchanged.

“If you listen to the number of calls, the emails that our offices are getting right now, the bombardment is pretty one-sided,” said South Dakota Sen. John Thune, No. 3 in GOP leadership. “That’s just the way it is.”

Kentucky Sen. Rand Paul, who was once viewed as a gettable vote, said, “There’s no great groundswell of Republicans telling me to vote for this.”…

Top Senate Democrats are prepared to push forward with a vote even if they can’t win more than just a handful of Republicans, believing public support for the proposal will grow and that Republicans will be eager to avoid a repeat of the political fallout they suffered after the failure of the 2007 immigration bill.