Sen. Elizabeth Warren officially jumped into the 2020 presidential race Saturday, joining a crowded field of Democratic challengers as she faces fresh criticism over her claims of Native American heritage.

"This is the fight of our lives. The fight to build an America where dreams are possible, an America that works for everyone," Warren said. "And that is why I stand here today: to declare that I am a candidate for President of the United States of America."

During her rally in Lawrence, Massachusetts, she also received some high-profile endorsements from several lawmakers, including Rep. Joe Kennedy III and Sen. Ed Markey, both key Democrats from Massachusetts.

"No one knows how to fight for what is right better than Elizabeth Warren," Markey said. "No one knows how to get under Donald Trump's skin better than Elizabeth Warren."

She touted her support for progressive politics, including increasing the minimum wage and Medicare for All. She propped up embracing diversity and the immigrants who helped build the nation, all with a backdrop of Everett Mills, the site of a workers strike 100 years ago led by women and immigrants that boosted workers rights.

She told the story of the strikes, using it as an example that even those without power can work together to shape policy and change America.

Warren already faces a sea of high-profile Democratic opponents contending for their party's nomination. Sens. Kamala Harris and Cory Booker announced their bids in recent weeks.

The Massachusetts Democrat announced her exploratory committee for her campaign on New Year's Eve but hadn't officially thrown her hat in the ring.

Warren, 69, has faced recent controversy over her past claims that she was of Native American descent.

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She apologized Wednesday for "not having been more sensitive about tribal citizenship" after The Washington Post published a 1986 Texas bar registration card where she listed her race as "American Indian."

"I'm not a tribal citizen," Warren told reporters. "My apology is an apology for not having been more sensitive about tribal citizenship and tribal sovereignty. I really want to underline the point, tribes and only tribes determine tribal citizenship."

Warren has apologized multiple times in the past month. In response to the Post's story, Warren said she "can’t go back," in terms of claiming the heritage and that she was sorry for "furthering confusion on tribal sovereignty" and the harm she caused.

In a private conversation, Warren told Cherokee Nation leadership that she was sorry about her DNA test that aimed to prove Native American ancestry, according to media reports.

The Massachusetts Democrat shared in October the analysis of her genetic background – which found "strong evidence" of Native American ancestry going back six to 10 generations. That decision faced backlash.

President Donald Trump, who could face Warren in the general election, has long derided her heritage claims and often refers to her as "Pocahontas."

After Saturday's announcement, Warren plans to head to New Hampshire, where the first primary will take place, and then Iowa on Sunday, home to key causes, the AP reported.

Contributing: William Cummings

This article originally appeared on USA TODAY: 'This is the fight of our lives': Elizabeth Warren officially announces 2020 bid