TONIGHT: @SenGillibrand stops by @colbertlateshow to announce that she is forming an exploratory committee to run for President of the United States! #LSSC pic.twitter.com/vPUpF1gs8z

— The Late Show (@colbertlateshow) January 15, 2019

So who is Kirsten Gillibrand (D-N.Y.), and what has she been up to since she entered Congress in 2009? The senator took over Hillary Clinton’s Congressional seat when Clinton became Secretary of State under President Barack Obama. Here’s a bit more about the last decade of Gillibrand’s career.

An advocate for women

Sen. Gillibrand is known for advocating for a national paid family leave policy. With her colleague Rep. Rosa DeLauro (D-Conn.), Gillibrand has been a force behind the Family And Medical Insurance Leave (FAMILY) Act, which would create a shared fund to make paid leave affordable to all employers.

Gillibrand has also publicly celebrated the opportunity to serve with a record number of women in Congress.

What an incredible privilege to be serving alongside so many women who are changing the face of leadership in this new Congress. https://t.co/UvYQXe39fL

— Kirsten Gillibrand (@SenGillibrand) January 15, 2019

As a Democrat, Gillibrand is also known for her pro-choice views.

It’s plain and simple: Women should have complete control over the decisions they make about their own bodies. There isn’t true equality without it.

— Kirsten Gillibrand (@SenGillibrand) November 17, 2018

The senator has also been vocal in the #MeToo movement and was a leading voice calling for the resignation of her former colleague, Sen. Al Franken, following allegations of sexual misconduct.

She is cleaning up campaign finance

In February 2018, Gillibrand announced that she would no longer accept money from corporate political action committees, or PACs. She called the effect of corporate money in politics “corrosive.” Massachusetts Senator Elizabeth Warren, who also announced her plans to enter the 2020 race, has also said she will reject corporate PAC money.

That doesn’t mean she hasn’t been fundraising. Gillibrand raised almost $18 million last year, and in the past 5 years more than $2 million came from lawyers and law firms, including $158,970 from her former employer, Davis, Polk & Wardwell, according to Open Secrets.

A force for (all) veterans

Along with several of her colleagues in Congress, Gillibrand has been working with a group of veterans advocating to change the motto on the Department of Veterans Affairs motto to include women veterans. About 10% of the 20 million veterans of the U.S. armed forces are women.

She rebooted her public image

Early in her career in Congress, Gillibrand ended up on the defensive about her legal career working as a defense attorney for tobacco giant Phillip Morris. In a profile in New York Magazine, she defended those decisions, saying she took on those clients in order to work on pro bono cases helping domestic abuse survivors get divorced and working with housing alliances to sue landlords that used lead paint.

She is unafraid to spar with President Trump

In 2017, Sen. Gillibrand and President Donald Trump traded tweets after Gillibrand called for Trump’s resignation following multiple sexual assault allegations that came out against him. She was one of four senators to do so—and the only female of the four. When Trump fired off a series of tweets, Gillibrand replied, “You cannot silence me.”

You cannot silence me or the millions of women who have gotten off the sidelines to speak out about the unfitness and shame you have brought to the Oval Office. https://t.co/UbQZqubXZv

— Kirsten Gillibrand (@SenGillibrand) December 12, 2017