In a party that is clearly moving left on economics, how can so many prominent Democratic senators support a bill so widely scorned by Democratic foreign policy experts? Because in recent years grassroots Democrats have turned their attention away from Middle East policy and AIPAC has not.

A few years ago, the backlash against such a bill would have been deafening. In 2007, Hillary Clinton voted to designate Iran’s Revolutionary Guard a terrorist group, a vote some feared gave the Bush administration license to attack Iran. Among her opponents for the Democratic nomination, the response was ferocious. “Instead of blocking George Bush’s new march to war,” declared John Edwards, “Senator Clinton and others are enabling him once again.” Candidate Obama mailed a flier to Iowa voters denouncing Clinton for her vote. Candidate Joe Biden called it a “serious, serious mistake.”

But back then, rank and file Democrats were still shaking with rage over Iraq. Over the last few years, the winding down of George W. Bush’s wars plus the financial crisis and rise of the Tea Party has radically reoriented the left’s focus. It’s a sign of the times that the party’s hottest star, Elizabeth Warren, is an anti-Wall Street crusader with no distinct foreign policy views whatsoever.