From Numbers USA (link):

For those of you whose primary political interest is stopping the growth of government or even shrinking it, you have to contend with national leaders who say they agree with you but who refuse to deal with immigration. They say immigration is a "social" issue that isn't related to government spending and deficit issues. They couldn't be more wrong...

...Even stranger is that this gargantuan driver of bigger and bigger government was promoted and continues to be supported by the Republican National Committee and by the Republican leadership of the U.S. Senate and House of Representatives.

Republican leaders every day castigate Pres. Obama for trying to bloat government, but Republican leaders resolutely refuse to even suggest that the government reduce its importation of welfare-using immigrants.

They also claim that "Roughly ONE-HALF of all immigrant households with kids are accessing the welfare system, especially food and Medicaid welfare".

While that focuses on the GOP, the same applies to libertarians and to other "fiscal conservatives", such as the tea parties and the "profits at any price" groups like Club for Growth.