Citing high demand, Democratic presidential candidate Bernie Sanders is moving the rally he's holding in downtown Denver on Sunday to a larger venue.

The Vermont senator plans to address supporters in the Colorado Convention Center's 12,000-capacity Exhibition Hall C/D, instead of the facility's Bellco Theater, which seats 5,000 people, his campaign said.

Colorado voters are receiving mail ballots for the March 3 presidential primary this week.

It will be the second visit to Colorado since Sanders launched his 2020 presidential campaign, and the first since he assumed the mantle of front-runner following a tie for first place in the Iowa caucuses and a win Tuesday in the New Hampshire primary. In September, 10,000 people filled Denver's Civic Center to hear Sanders speak.

The rally is scheduled to start at 6 p.m., and doors open at 4 p.m. Tickets aren't required, but the Sanders campaign urges attendees to RSVP here.

Presidential candidates are beginning to swarm Colorado as the state's Super Tuesday primary approaches.

Former Mayor Pete Buttigieg, who leads the field in delegates following the first two contests, is set to hold a town hall on Feb. 22 in Aurora.

President Donald Trump, who doesn't face significant opposition in Colorado's Republican primary, is holding a rally on Feb. 20 in Colorado Springs.

Sanders held a rally inside the Colorado Convention Center in 2016, weeks before his 20-point win over former Secretary of State Hillary Clinton in Colorado's caucuses.

That same year, Colorado voters approved a move from caucuses to a presidential primary to determine how the state's Democratic and Republican national convention delegates are apportioned.