Former Denver mayor and national Democratic party leader Wellington Webb will rally supporters for candidate Michael Bloomberg at an office in Jefferson County as voters start to return primary ballots.

Webb will kick off a canvass of voters 10 a.m.-noon at a Bloomberg field office at 5091 Kipling St. in Wheat Ridge. It’s one of nine offices the billionaire and former New York mayor is opening across the state ahead of Colorado’s March 3 primary.

Bloomberg is skipping the four early states that vote in February and is instead spending big on Super Tuesday, when 14 states weigh in, including Colorado.

Bloomberg has visited Colorado three times since he launched his campaign in late November. He unveiled his gun control agenda in Aurora in December and revved up a crowd at an office opening in Denver’s Lower Downtown earlier this month, drawing more than 1,200 people.

The Bloomberg campaign is banking on strong showings in a crowded primary field that hasn’t winnowed much since the Iowa and New Hampshire contests.

Bloomberg has ramped up a massive operation in Colorado, including more than 50 paid staffers and dozens of prominent endorsers. The self-funding candidate, who is worth more than $60 billion, has spent more than $300 million in advertising nationwide.

Webb endorsed Bloomberg this week, amid fresh controversy over the “stop-and-frisk” policy aimed disproportionately at young African-American men, which Bloomberg once championed but has since disavowed and apologized for.

Webb, Denver’s first African American mayor and a leading figure in state and national politics for decades, was named a co-chair of the Mike for Black America National Leadership Council, Bloomberg’s campaign said.

The spotlight is turning to Colorado and other Super Tuesday states, including California and Texas.

Vermont Sen. Bernie Sanders, the primary’s front-runner after finishing in a virtual tie for first place in the Iowa caucuses and winning the New Hampshire primary by a narrow margin, is set to appear at the Colorado Convention Center on Sunday in a space that holds 12,000 people.

Pete Buttigieg, the former South Bend, Indiana, mayor, has a town hall scheduled on Feb. 22 in Aurora, and his husband, Chasten, is appearing at two events in Denver on Sunday.

Although he doesn’t face significant opposition in the Republican primary, President Donald Trump has planned a rally with U.S. Sen. Cory Gardner on Thursday in Colorado Springs.

Editor’s note: This story was updated to correct that Wellington Webb, who has endorsed Mike Bloomberg, is opening the Wheat Ridge office, not Bloomberg.