WASHINGTON — Former President Barack Obama is starting to define his new role in the age of Donald Trump.

After dropping out of sight for a pair of glamorous island getaways, Obama is emerging for a series of paid and unpaid speeches, drawing sharp contrasts with Trump even as he avoids saying the new president’s name. He’s wielding his influence overseas, offering his support for some of the international political candidates who are clamoring for his endorsement. His aides are engaging in real-time political combat with Trump, including revealing Monday that Obama personally warned his successor against tapping embattled Michael Flynn as his national security adviser.

Obama’s swift return to the spotlight has been cheered by some Democrats, who are still sifting through the wreckage of the party’s crushing defeats in the November election. But the attention surrounding Obama has also magnified the vacuum for new Democratic leadership, a reality that aides say is not lost on the former president.