An interesting bit of information from a recent Pew Poll:
Fully 71% of conservative Republicans think the U.S. should support Israel’s military action if they attack Iran, compared with 43% of moderate and liberal Republicans. A majority of independents and Democrats (including both liberal and more moderate Democrats) think the U.S. should stay neutral.
There's also growing concern, according to the poll, that sanctions aren't working:
And the Tea Party is tough:
An overwhelming majority of Republicans and Republican-leaning independents who agree with the Tea Party (84%) say that the U.S. should prevent Iran from developing nuclear weapons, even if it means taking military action. That compares with a smaller majority (64%) of Republicans who disagree with or have no opinion of the Tea Party.