This is a foreign policy doctrine issue, not a political issue.
On one side are the NeoCon republicans aligned with the Liberal Interventionist democrats versus the Realists who can be a democrat or republican.
To put it another way: Republican Senator Mark Kirk and Democrat Senator Robert Menendez versus Republican Senator Bob Corker and Democrat Senator Diane Feinstein.
Or to put it another way: AIPAC versus J Street
There is nothing realist about an ideology that declare ideology irrelevent. And there is nothing realist about allowing Iran to have nukes. It’s suicide by cowardice.