It’s been Washington’s worst kept secret for months, but finally, Joe Biden has formally entered the race to become the next U.S. president.

The former vice-president made the announcement in a Twitter video early Thursday, joining an already swollen pool of 19 Democratic Party candidates.

In the video message, Biden says Americans are “in the battle for the soul of this nation” and that the country’s core values are in danger.

Democratic strategist Christy Setzer says the message was spot on.

“It basically says to America: ‘remember what were all about here.’ He’s somebody who, again, having been the vice-president for eight years, having somebody who has a ton of gravitas on the national and international stage, can deliver that message, especially in stark contrast to Donald Trump,” she said Thursday, appearing on CTV News Channel.

Trump wasted no time commenting on Biden’s announcement. In a tweet, Trump said, “Welcome to the race Sleepy Joe. I only hope you have the intelligence, long in doubt, to wage a successful primary campaign. It will be nasty.”

Trump’s 2020 re-election team has said that there are a few Democratic candidates they’re concerned about running against, with Biden being at the top of that list. Setzer says it’s probably because Biden and Trump go for the same core voters: white working-class men.

“There’s an appeal that Biden has, we believe, with that set of voters that has just not been true of other Democrats that are in the race, or of that many Democrats in the race,” she says.

Other high-profile names in the running include Bernie Sanders, Beto O’Rourke, Elizabeth Warren, Kamala Harris, and Pete Buttigieg.