I was an early supporter of Bernie Sanders. Yes, I was feeling the Bern. But today, I am proud to endorse Hillary Clinton for President of the United States. She offers strong progressive values, a remarkable tenacity of spirit, and has demonstrated a capacity to listen.

During the campaign, I was impressed by how seriously Secretary Clinton heard and respected the progressive movement. We saw her talk with Black Lives Matter activists about systemic racism. We saw her listen to environmentalists about their concerns about the Keystone pipeline. We saw her stand with labor activists in opposition to the Trans-Pacific Partnership.

That willingness to include the progressive movement led to the most progressive platform in the history of the Democratic Party. Serving on the Platform Drafting Committee, I witnessed firsthand the unity and shared values of the two campaigns on critical issues - from raising the minimum wage to $15 an hour, to strong criminal justice language on demilitarizing the police and requiring body cameras, to calling for a financial transactions tax to curb excessive Wall Street speculation.

But I'm not surprised. Hillary Clinton has progressive roots and values. For decades, she has fought for the issues today's movement marches for - expanding health care, immigration reform, and fighting for better wages and working conditions.

And within the last week she has announced two historic plans: one to make public colleges and universities tuition free for more than 80% of American students, and a second to double funding for primary health care services at community health centers.

But her willingness to listen and her progressive values aren't all that has impressed me. It has also been her tenacity and resilience. We all remember when Majority Leader Kevin McCarthy accidentally told the truth by confessing, "Everybody thought Hillary Clinton was unbeatable. But we put together a Benghazi special committee, a select committee. What are her numbers today? Her numbers are dropping." Despite the committee spending $7 million and more than a year of investigation, Secretary Clinton withstood the attacks - facing down an 11-hour grilling with poise - and was completely vindicated.

Attacks are nothing new to Hillary Clinton. For more than 25 years, she has faced a relentless attack machine that has sought to slander her name and distort her record. Yet, she continues to fight. Like a tree with strong roots, she may bend, but she will never break.

She brings this into the general election against Donald Trump. She is committed to turning around Democrats' slide at the state and local level, and she's launched a crucial 50-state strategy to build the infrastructure we need to win.

Throughout the primary, Bernie showed the true power of a grassroots organizing campaign. 13 million Americans - many participating in the democratic process for the first time - voted for progressive values in every part of the country. Bernie's events saw record crowds: 11,000 in Phoenix; 14,000 in St Paul; 28,000 in Brooklyn. Voters were so energized by Bernie's message that nearly 2.5 million donors gave an average of $27 to support his presidential race, turning conventional thinking about campaign funding on its head.

Our movement is just beginning. We must stay energized and organized to elect progressives at all levels of government - from city councils to school boards, governorships to senate seats.

Bernie said many times our movement was never about him. It was about tackling income inequality, getting big money out of politics, and ending crippling student debt.

We can accomplish these goals and more with the progressive movement united to defeat Donald Trump. He has called Mexicans rapists and criminals, he wants to ban all Muslims - nearly one-quarter of the world's population - from entering the United States, and he has repeatedly degraded women. He is unfit to lead this great country and I will join Hillary, Bernie and their supporters to do everything in our power to ensure he never gets the chance. The stakes in this election couldn't be higher.

Hillary Clinton is the most qualified nominee in history and there is no question that she stands firmly for progressive values.

As a progressive, that means I'm with her.