Quoting from this site:
Frist initially advanced a bill largely limited to border security. He then embraced Bush’s concept of a broader measure including provisions relating to illegal immigrants. But in doing so, he left behind GOP conservatives, who see the measure as offering amnesty to lawbreakers.
Because, of course, no Republican has ever broken the law, especially not for so worthless a reason as getting a job to feed their family.
Shoot ’em all, I say.