From Time:
A new survey could ease Republican fears that proceeding with immigration reform would alienate GOP voters.

The poll, conducted by Texas Republican firm Baselice & Associates and paid for by the Michael Bloomberg-sponsored pro-reform group Partnership for a New American Economy, found that there is no measurable drop in voter turnout when comparing the immigration positions of three Texas congressional Republicans. The poll focused on three districts with GOP incumbents: Rep. Sam Johnson, who is supportive of immigration reform, Rep. Lamar Smith, who is against it, and Rep. Kevin Brady, who is on the fence. Support of or opposition to immigration reform didn’t impact voter support at the polls, according to the survey.

The results cut against Republican concerns that passing immigration reform will keep their base voters away from the polls this fall, and indicates that the economy and the health care reform law are the key issues driving voters.

This poll is just the latest report warning mainstream GOP members that they should not buy the argument of extremists in the party trying to convince them that their views are widely held even with base GOP supporters. Even those opposing immigration reform in the GOP don't usually make it a litmus test for supporting a candidate. Those that do, according to many polls, amount to only a small number of individuals.