WASHINGTON — Speaker John A. Boehner’s unilateral invitation to Prime Minister Benjamin Netanyahu of Israel to address Congress on Tuesday has turned a foreign policy issue that has had near unanimous support in both parties — Israel — into a bruising political showdown.

And nowhere has that transformation been more wrenching than among Jewish members of Congress — all but one of them Democratic — who seem to reflect the dismay of the nation’s larger Jewish community over the House speaker’s action.

“I went out to play golf — I never play golf — with three of my Jewish buddies,” recalled Representative Alan Lowenthal, a Jewish Democrat from Southern California who only this weekend decided he will attend Mr. Netanyahu’s address to a joint meeting of Congress. “One said, ‘You must go,’ one said, ‘You definitely should not go,’ and one said, ‘I’m in the middle.’ That literally reflects the American Jewish community.”

Through foreign policy trials as difficult as the wars in Gaza and Lebanon, Israeli settlement policies, Arab terrorism, and the repeated failures of Israeli-Palestinian peace talks, Jews in Congress — and to a large extent, Jews in the United States — have spoken in a near-monolithic voice, always in support of the government of Israel.