Sanders wasn’t going to be the Democratic nominee, but he still held a good amount of leverage in the form of his voters. After a tough primary, they were hesitant to back Clinton, a fact apparent in the polls. Clinton stood ahead of Donald Trump, but not by much: Her lead was weakened by the party’s unbridged divisions. By holding off on a concession and an endorsement, the Vermont senator was keeping this leverage in reserve ahead of the Democratic National Convention. It made sense.

Still, it was a risky move. Whatever influence or leverage Sanders had was tied to his voters. As long as they stuck with him—and didn’t move to Clinton—he could make demands and win concessions on items like the Democratic Party’s platform, a key object of his rhetoric over the past month. But if his voters moved without his endorsement, either pushed by fear of Trump or support from other Democrats, then the value of his support would fall accordingly.

Which is what happened. In his nonconcession speech, Sanders told supporters their “major political task” was to “make certain that Donald Trump is defeated and defeated badly.” It turns out that was the message that landed.

In the most recent poll from ABC News and the Washington Post, Clinton leads Trump 51 percent to 39 percent, expanding her previous lead by 5 points, as Trump has seen a complete collapse in his support. And what’s driving the move toward Clinton? Democrats and independents who supported Bernie Sanders. In May, 20 percent of Sanders supporters said they would back Trump over Clinton in the general election. In June, that number is down to 8 percent. Overall, 81 percent of Sanders backers have rallied to Clinton, surpassing the 74 percent of Clinton supporters in 2008 who fell in behind Barack Obama. By any measure, the Democratic Party is unified.