Pro-Israel Democrats will have their reputations stained forever if they let this Iran deal pass

The Democrats’ historic support for the Jewish state has always been what’s best about the party. The understanding not only that Jews are entitled to a state, but also that a liberal democracy is entitled to defend itself—robustly and sometimes pre-emptively—against illiberal enemies, is why the party of Harry Truman, Scoop Jackson and Daniel Patrick Moynihan commands historic respect.

But that party is evaporating. A 2014 Pew survey found that just 39% of liberal Democrats are more sympathetic to Israel than they are to the Palestinians. That compares with 77% of conservative Republicans. During last summer’s war in Gaza, Pew found liberals about as likely to blame Israel as they were to blame Hamas for the violence.

That means the GOP is now the engine, the Democrats at best a wheel, in U.S. support for Israel. The Obama administration is the kill switch. Over the weekend, a defensive White House put out a statement noting the various ways it has supported Israel. It highlighted the 1985 U.S.-Israel free-trade agreement and a military assistance package concluded in 2007. When Barack Obama must cite the accomplishments of Ronald Reagan and George W. Bush as evidence of his pro-Israel bona fides, you know there is a problem.