How Obama's bitter feud with Trump drives Dems' campaigns

• Obama is motivated by his deep concern about Trump's temperament and policies, but also by a personal animus that began in 2011, when Trump aggressively promoted the "birther" conspiracy theory — the false idea that Obama hadn't been born in the U.S., and therefore wasn't eligible to be president.
• Asked about Obama's feelings toward Trump, Bill Daley, Obama's chief of staff in 2011, told Axios: "You cannot underestimate the birth certificate thing — that was an attempt to totally discredit his credibility as a person."

Driving the news: Obama, along with his wife Michelle, took off their gloves and pummeled Trump last night at the Democratic National Convention. They went low.

• "Here is a 78-year-old billionaire who hasn't stopped whining about his problems since he rode down his golden escalator nine years ago," Obama said.
• His wife got even more personal.
• "His limited and narrow view of the world made him feel threatened by the existence of two hardworking, highly educated, successful people who also happened to be Black," Michelle Obama said, to roars of approval from the crowd.
• "It's his same old con: doubling down on ugly, misogynistic, racist lies as a substitute for real ideas and solutions that will actually make people's lives better," she added.

Zoom out: Barack Obama, for all his efforts to defeat Trump, knows that he helped to create him.

• At the 2011 White House Correspondents' Dinner in Washington, then-President Obama answered Trump's ugly "birther" allegation with a withering indictment of Trump.
• Obama's advisers had counseled against it, but Obama used the dinner to humiliate Trump.
• "He went way overboard," Daley said. "I, even as chief of staff, was like, 'Maybe we are going too far there.' Didn't matter."

Trump was publicly embarrassed, but privately energized. Five-and–a-half years later, he was president.

• After Trump's victory in 2016, Obama was frustrated and believed he could have beaten Trump if the Constitution would have allowed him to seek a third term.
• "I'm confident that if I had run again and articulated it, I think I could have mobilized a majority of the American people to rally behind it," he said in December 2016.

Zoom in: For most of his time in office, Trump was just as personal in describing Obama, but recently Trump has been kinder to the man he replaced in the White House.

• "I happen to like him," Trump told CNN Tuesday. "I respect him and I respect his wife."
• As president, Trump struck a far different tune and was dedicated to undoing Obama's legacy.
• Trump withdrew from the Iran nuclear deal to "spite" Obama and repeatedly tried to repeal his signature health care law.

The intrigue: In 2020, Obama had deep concerns about Sen. Bernie Sanders' electability in a general election at a time when it appeared Sanders could be the Democratic nominee, according to people familiar with the matter.

• Obama stayed neutral for most of the primary season but when his former vice president Joe Biden had a big win in South Carolina, Obama helped Biden consolidate the Democratic field against Sanders and unite the party after the tough primary.
• Many former Obama aides then joined Biden's presidential campaign in senior roles — occasionally prompting frustration from Biden's primary team who felt they were being layered by the newcomers.
• Biden went on to beat Trump in the general election, in a campaign many Democrats assumed would end Trump's political career.

Go deeper: This June, after Biden fumbled his debate against Trump, Obama didn't stand in the way of the efforts to push Biden aside — a movement that included former Obama aides and friends of the ex-president such as actor George Clooney, a Democratic donor.

• When Biden dropped out and endorsed Harris, many current and former Obama advisers joined Harris' campaign in senior roles.

The bottom line: In 2016, Obama would have campaigned hard for the Democratic candidate, regardless of who the GOP nominee was, according to one senior Democrat.

• Similarly, this year he was prepared to campaign for Biden (and now Harris) no matter whom the GOP nominated, the Democrat said.
• But his ad hominem attacks on Trump — including last night's dig about Trump's "weird obsession with crowd sizes" — are clearly just as personal as they are political.

Go deeper... "Yes, she can": 5 takeaways from Obama Night at the DNC