State Sen. Angela Williams on Monday became the latest Democrat to join a crowded primary to take on Republican U.S. Sen. Cory Gardner.

The northeast Denver lawmaker becomes the 11th declared candidate and the first sitting elected official declaring a bid to unseat Gardner, considered among the most vulnerable GOP senators up for election next year.

“Throughout my career in public service and in the private sector, I’ve been driven by the values of hard work, honesty and standing up for others. Those are the values I want to take to the United States Senate,” Williams said in a statement.

Added Williams: “Cory Gardner and Donald Trump have sought to divide Coloradans and Americans for far too long. Their days of standing up for special interests at the expense of working families in Colorado are over. I’m eager to go to Washington to bridge the divide and tackle the toughest challenges facing our state and our nation.”

After serving three terms in the Colorado House of Representatives, Williams won election in 2016 to the Senate District 33 seat previously held by Democrat Mike Johnston, the fundraising frontrunner in the U.S. Senate primary.

The chair of the Senate Business Labor & Technology Committee, Williams has developed a reputation as a business-friendly Democrat. She has also spearheaded prominent criminal justice reform legislation, including this year’s ill-fated death penalty repeal and a 2013 law that compensates the wrongly convicted $70,000 for each year spent in prison.

Williams allies have been teasing her entry into the Senate race for months, and she told Politico in May that she had recently met with Senate Democrat Leader Chuck Schumer to discuss a run against Gardner.

Politicians who have said they’re considering joining her include U.S. Reps. Ed Perlmutter and Joe Neguse, as well as Secretary of State Jena Griswold and state Sen. Kerry Donovan of Vail.

Former Gov. John Hickenlooper has been facing increasing pressure – including from senior staffers, who have since departed or given notice to his campaign – to ditch his presidential ambitions and instead challenge Gardner, but the moderate Democrat has insisted he isn’t cut out for the Senate.

In addition to Johnston, the other candidates running in the primary are former state House Speaker Andrew Romanoff, former ambassador Dan Baer, former U.S. Attorney for Colorado John Walsh, former state House Majority Leader Alice Madden and former congressional candidate Stephany Spaulding.

First-time candidates in the race are scientist Trish Zornio, community organizer Lorena Garcia, climate activist Diana Bray and economist Ellen Burnes.