Former U.S. Sen. Mark Udall and his wife, Maggie Fox, on Monday endorsed Joe Biden for president, joining Denver Mayor Michael Hancock in throwing their support behind the former vice president.

They were among several establishment Democrats nationally to back the former vice president as he seeks to consolidate support the day before Super Tuesday contests, including the Colorado primary. By late morning, news outlets also reported that U.S. Sen. Amy Klobuchar, a fellow candidate, was dropping out and endorsing Biden.

“Our country faces immense challenges,” Udall said in a statement provided by Biden’s campaign. “We know Joe Biden is someone who can unite our party and country, restore dignity to the White House and rebuild trust in our government.”

Udall is a former congressman from Eldorado Springs who then served one term in the U.S. Senate before he was defeated by current Sen. Cory Gardner in 2014. Maggie Fox is an environmental attorney and activist who formerly headed the Climate Reality Project and the Climate Action Fund.

“On Day One, Joe Biden will be able to repair the damage done by Donald Trump and his attacks on healthcare, immigrants and the environment,” Fox said.

Earlier Monday, Hancock called the election “the most critical decision of this generation” and said in a statement that Biden is “the best qualified to heal the wounds of division that have been sown under Trump.”

The mayor, a prior backer of former Colorado Gov. John Hickenlooper and U.S Sen. Michael Bennet until each dropped out of the Democratic presidential race, held off through February on endorsing one of the remaining candidates. Neither Bennet nor Hickenlooper has endorsed an active candidate, and campaign contacts for both said Monday that neither was prepared to do so yet.

BREAKING: AP sources say Pete Buttigieg to endorse Joe Biden at Monday rally in Dallas as Democratic moderates seek to unite behind the former vice president. https://t.co/ubnKEnmtRT — The Associated Press (@AP) March 2, 2020

“Joe Biden is the president our country needs,” Hancock said. “I know he’ll unite our nation and get to work immediately delivering for working families. … As the mayor of a growing and vibrant city, Donald Trump’s reckless attacks on immigrants, health care and the environment are deeply personal. Joe is a candidate that has both the experience and the ability to get our country back on track.”

Colorado is among 15 states and territories with Super Tuesday contests this week. Voting has been underway in Colorado since mid-February, and the field has narrowed in recent days after former South Bend Mayor Pete Buttigieg and billionaire activist Tom Steyer ended their campaigns, leaving six major candidates.

Biden notched his first victory Saturday with a huge win in the South Carolina primary over U.S. Sen. Bernie Sanders. But elsewhere, he is competing with other candidates to unite moderate-minded voters against the more liberal Sanders.