“Now, you have the standard-bearer of the Tea Party saying that we should welcome undocumented immigrants as Americans,” said Frank Sharry, executive director of America’s Voice, a pro-immigration group. “It’s one of the fastest turnarounds I’ve seen on any issue. It’s mind-blowing.”

Bob Dane, a spokesman for the Federation for American Immigration Reform, which opposes a path to citizenship for illegal immigrants, conceded Tuesday that “it certainly appears to be settled if one assumes that the inside Republican elite strategists represent the core of the Republican Party.”

But it remains to be seen how Republican voters and conservative activists across the country will respond to proposals that allow illegal immigrants to live in America and compete legally for jobs. Mr. Dane’s group is meeting with 52 talk radio hosts in Washington next month for a two-day session intended to bolster opposition to the idea…

“I think they’ve found themselves on the road to Damascus, or they understand that this issue is very, very important,” said Senator John McCain, Republican of Arizona, who is part of the bipartisan group in the Senate working on immigration legislation.

Senator Lindsey Graham, Republican of South Carolina and another member of the Senate group of eight, put it more bluntly: “I just think the 2012 election was a bit of a wake-up call.”