Big Money Donors Lobby Lawmakers On Iran Deal

In the weeks before Senator Chuck Schumer’s decision to oppose the Iran nuclear accord, John Shapiro, a New York financier and a leader of the American Jewish Committee, had his ear, plying him with reasons to oppose it.

Mr. Shapiro, a longtime benefactor of the New York senator and other Democrats, was hardly alone. Some of the wealthiest and most powerful donors in American politics, those for and against the accord, tried to get a word in with Mr. Schumer. Now, approaching a vote on President Obama’s most important international priority, the fight is expanding, with tens of millions of dollars flowing into ad campaigns, and contributors leveraging access to undecided Democrats.