Launching her bid for the White House on Wednesday, situated outside her favorite diner, Senator Kirsten Gillibrand said she would present the best case for taking on President Donald Trump.

"Despite all our flaws, we want to bring people together not tear them apart. Until now, until now. Until President Trump has chosen to tear this country apart," Gillibrand said.

Gillibrand last year, as she ran for re-election, pledged to serve out her full six-year term in the U.S. Senate. Gillibrand explained why she changed her mind.

"This sense of urgency has only grown in me, and I wanted to talk to my family. I've got really cute kids, wonderful children and they will be making sacrifices too," Gillibrand said.

Gillibrand comes from a family steeped in politics. Her grandmother, Polly Noonan, was a top aide to Albany Mayor Erastus Corning.

"I know that I have the compassion and the courage and the fearless determination that is necessary to get this done. I know this because of all the people on whose shoulders I stand," Gillibrand said.

First elected in 2006 to a Republican-leaning House district, Gillibrand held centrist and conservative views on the budget, gun control and immigration — views that have since changed after she was appointed in 2009 to fill Hillary Clinton's Senate seat. 

"I think it's important to know when you're wrong and to do what's right, and I will do what's right, I will fight for what's right, and I don't back down from those fights," Gillibrand said.

She is also running without the support of her former boss at the Department of Housing and Urban Development, where she was a top attorney for then-Secretary Andrew Cuomo. The governor is backing former Vice President Joe Biden, should he enter the race. Gillibrand is still holding out hope for support.

"I intend to try to change everybody's mind," Gillibrand said.

Gillibrand will be traveling to Iowa soon as the state prepares for its first-in-the-nation caucus.