[Source: Reuters]

Former U.S. President Barack Obama returns to the national stage on Tuesday night to boost his longtime Democratic ally Kamala Harris in her 11th-hour presidential bid against Republican Donald Trump.

America’s first Black president, Obama has thrown his considerable political capital behind Harris as she seeks to make history herself on Nov. 5 as the first woman and first Black and South Asian person to be elected U.S. president.

Obama will be preceded by his wife Michelle, who tops Democrats’ wish list as a future president.

Republicans who have left the fold since Trump’s takeover of their party crossed the aisle on Tuesday night to address the convention, including Trump’s former White House press secretary Stephanie Grisham and former Trump voter Kyle Sweetser.

Later in the evening, Republican Mayor John Giles of Mesa, Arizona, was due to speak.

Grisham described her journey from a Trump “true believer” to the first senior White House staffer to resign after the Jan. 6, 2021, attack by Trump supporters on the U.S. Capitol.

Conservative voters who dislike Trump have been one of the Democrats’ hoped-for prizes. The challenge will be persuading them to get to the ballot box in November and vote for Harris, versus staying home or writing in a presidential candidate.

Harris’ fledgling campaign, still light on policy specifics, has coasted on the enthusiasm of Democrats relieved by the departure of Joe Biden, a beloved 81-year-old president who had become a liability.

Obama will outline what he believes will lift Harris to victory while also warning Democrats about the tough task they face over the next 11 weeks, according to a source familiar with the remarks. The former first lady will emphasize the need for the country to turn the page on fear and division.

U.S. Senator Bernie Sanders will speak along with Senate Democratic Leader Chuck Schumer, Illinois Governor J.B. Pritzker and Douglas Emhoff, Harris’ husband.

Trump and his vice presidential running mate, JD Vance, are barnstorming battleground states this week in a bid to steer attention away from the convention in Chicago and highlight Trump’s policy differences with Harris.

At a campaign stop in Howell, Michigan, Trump repeated unsupported claims that Harris took a permissive approach to law enforcement.

Trump spoke one month after white supremacists rallied in the small town. Trump himself has made racist remarks about Harris.

Harris and her vice presidential pick, Minnesota Governor Tim Walz, traveled to Milwaukee on Tuesday for a campaign rally in the same venue as last month’s Republican National Convention, where Trump formally received his party’s nod.

Her remarks will be livestreamed into Chicago’s United Center, a basketball and hockey arena and site of the convention.