Sen. Elizabeth Warren has made it official: she is jumping into the presidential race. The Massachusetts Democrat became the first major Democratic candidate to enter the 2020 contest when she announced Monday that she is forming an exploratory committee. That key step allows her to hire staff and start raising money before she formally kicks off her candidacy in what is likely to be a crowded Democratic primary. Others, including some of Warren’s fellow senators, are also getting ready to make announcements of their own, and some are expected within days, according to the Washington Post.

“America’s middle class is under attack,” Warren says in a four-minute, 30-second video emailed to supporters Monday morning in which she made the announcement. “How did we get here? Billionaires and big corporations decided they wanted more of the pie. And they enlisted politicians to cut them a bigger slice.” Throughout the video, Warren leans in to her reputation as an anti-Wall Street crusader who has a working class background and has long advocated for stronger consumer financial protections.

“I’ve spent my career getting to the bottom of why America’s promise works for some families, but others, who work just as hard, slip through the cracks into disaster,” Warren, 69, says in the video. “And what I’ve found is terrifying: these aren’t cracks families are falling into, they’re traps. America’s middle class is under attack.”

Warren’s candidacy hardly comes as a surprise. Many progressives pushed the senator to run in 2016 but she passed. President Donald Trump is likely to be happy that Warren is entering the field as he seems to have been preparing to run against her. The president has frequently criticized her and seems to take great pleasure in calling her “Pocahontas” in reference to accusations that she has misrepresented her Cherokee heritage for professional gain. Earlier this year, in a move many saw as confirmation that she was getting ready to launch a presidential bid, she released the results of a DNA test that showed she did have Native American ancestry. Yet that move also engulfed her in controversy as many progressives criticized her move, saying she took Trump’s bait and in the process “put too much emphasis on the controversial field of racial science,” as the New York Times put it in a piece earlier this month. It hardly seems a coincidence that the video she emailed to supporters Monday made no mention of the DNA test.

Other senators that are expected to announce presidential runs include Cory Booker of New Jersey, Kamala D. Harris of California, Sherrod Brown of Ohio, Amy Klobuchar of Minnesota, Kirsten Gillibrand of New York, and Bernie Sanders of Vermont. Former Vice President Joe Biden is also seen as a possible contender.

Warren now faces two key challenges. The Washington Post’s Jennifer Rubin explains:

First, she’ll need to distinguish herself from the crowd (A less cranky Sanders? A more progressive Gillibrand?). While she may drain support away from Sanders, her toughest competitor for the blue-collar populism crowd might be Brown, whose everyman style and Rust Belt roots give him an advantage over a wonkish former law professor. Second, and perhaps most critical, is the challenge of finding a voice and a message that will appeal both to Democrats’ hearts and heads. Certainly, primary voters want to swoon over an articulate, charismatic figure, but more than anything, they want to win. Warren will have to wow voters with passion while convincing them she can hold her own against Trump, a task made harder by her DNA flub.

Warren is expected to unveil a travel schedule soon that will see her going to the first presidential primary states in the coming weeks, including Iowa and New Hampshire. Iowa is holding its caucus in early February 2020.