Colorado voters have returned more than 570,000 ballots so far, ahead of the state’s first presidential primary election in decades. 

The 573,707 ballots returned are as of Monday, according to a report from the polling firm Magellan Strategies. County clerks across the state update their ballot return numbers throughout the day as ballots are received, so data is constantly changing.  

This is the first year in decades that Colorado will hold a presidential primary election, this year joining 13 other Super Tuesday states. Previously Colorado held party caucuses. 

Among the returned ballots, 246,240 were from Republicans, 160,202 from Democrats, and 163,224 from unaffiliated voters.

“It would make sense if Democratic voters are simply waiting to see what happens this week in the form of the daily news cycle, [today’s] debate or the actual results from South Carolina on Saturday,” Magellan Strategies said. “A whole lot can change in a week, and we fully expect ballots to come pouring in over the weekend as well as next Monday and Tuesday.”

The most recent polling for the Colorado Democratic Primary is from August, with U.S. Sen. Bernie Sanders, I-Vt., having 26 percent support, followed by former Vice President Joe Biden at 25 percent and Sen. Elizabeth Warren, D-Mass., at 25 percent. Billionaire Michael Bloomberg had not announced his campaign at the time of the poll, and several other candidates have since dropped out.

RealClearPolitics’ national polling average has Sanders (29.3 percent) leading Biden (17.2 percent) and Bloomberg (15.3 percent).

Voters have until 7:00 p.m. on March 3 to turn in their ballots.