WASHINGTON (AP) � Nearing the end of a lengthy primary fight, Democrats are coalescing around Hillary Clinton�s presidential bid and looking to reunite the party through a carefully orchestrated plan aimed at nudging rival Bernie Sanders to make his exit.

President Barack Obama�s endorsement of his former secretary of state on Thursday headlined a day of unity for Democrats as the party prepares for Republican Donald Trump. Amid the message of harmony, Sanders crisscrossed the nation�s capital and received praise in meetings with Obama, Vice President Joe Biden and Senate Democratic leaders.

On Thursday night, Sanders� District of Columbia rally outside RFK Stadium didn�t mention Clinton and didn�t repeat his calls to persuade superdelegates to support him or his plans for a contested convention in Philadelphia. The Vermont senator barely mentioned Tuesday�s primary election in the city, the last on the Democratic calendar.

�It would be extraordinary if the people of Washington, our nation�s capital, stood up and told the world that they are ready to lead this country into a political revolution,� Sanders said in the final sentence of his hourlong address.

Democrats are wary that divisions that emerged between Clinton and Sanders during the primaries might spill out during next month�s Democratic National Convention or provide an opening to Trump, who is on course to become the Republican nominee. So unity has become Job 1 in the party.

In his long-expected endorsement, delivered via an online video, Obama pointed to Clinton�s grit and determination but also called for �embracing� Sanders� economic message, which has galvanized liberals and independents. Obama sought to reassure Democrats that Clinton shares their values and is ready for the job.

�Look, I know how hard this job can be. That�s why I know Hillary will be so good at it,� Obama said. The president plans to campaign next week with Clinton in Green Bay, Wis., marking his first major foray into the 2016 campaign.

Trump responded to Obama�s endorsement by tweeting: �Obama just endorsed Crooked Hillary. He wants four more years of Obama � but nobody else does!�

The Clinton campaign tweeted back, �Delete Your Account.�

Obama�s testimonial came less than an hour after he met privately with Sanders at the White House to discuss the future of the senator�s �political revolution.�

While Sanders stopped short of endorsing Clinton, he told reporters he planned to press for his issues � rather than victory � at the party�s convention and he would meet with Clinton in the near future to discuss ways they could work together to defeat Trump.

Clinton declared victory over Sanders on Tuesday, having captured the number of delegates needed to become the first female nominee from a major party. Her extended primary campaign against Sanders, who entered the race as an obscure independent, had set off a round of private phone calls and back-channel negotiations, all aimed at addressing Sanders� issues while easing him out of the race without angering his die-hard supporters.

Obama�s endorsement and Sanders� visit were the public culmination of that work.