CO Reps. Emily Sirota and Jeni James Arndt

Colorado Democratic Reps. Emily Sirota (L) and Jeni James Arndt (R) speak before the passage of their national popular vote bill, which is headed to Gov. Jared Polis, who's expected to sign the bill.

The Colorado General Assembly approved a bill on Thursday that could overhaul how Colorado casts its votes in presidential elections, sending the legislation to Gov. Jared Polis’s desk.

Senate Bill 19-042 adds Colorado to the National Popular Vote Interstate Compact and requires the state’s nine electoral college votes be awarded to the presidential candidate who wins the national popular vote.

Senate Democrats passed the bill last month and House Democrats approved the legislation Thursday. Polis has previously expressed support for national popular vote.

There are currently 538 electoral votes divided between the 50 states and the District of Columbia, with 270 votes required to win the U.S. presidential election.

Democrats nationally have flirted with the idea of a national popular vote for some time, citing the 2016 election when Democratic nominee Hillary Clinton won the popular vote but lost the electoral vote to Republican nominee Donald Trump. It similarly happened in 2000, when George Bush won the electoral college against Al Gore, who won the popular vote.

Democrats believe joining the compact would prevent election outcomes like in 2000 and 2016.

Colorado Secretary of State Jena Griswold in January testified in favor of the bill, and progressive groups like ACLU Colorado and Colorado Common Cause support the legislation, saying joining the pact would assure “each American’s ballot counts equally.”

Colorado Republicans and conservative groups have opposed the bill, saying it tampers with the U.S. Constitution and could make Colorado voters irrelevant.

Electors in states that enter the compact are required to cast their vote for the candidate who wins the national popular vote. As law, Colorado’s electors would be required to vote for the winner of the national popular vote even if that candidate did not win a majority of votes in the state.

If Polis signs the bill, Colorado will be the 13th state to join the compact. The 13 states combined hold a total of 172 electoral votes. The measure takes effect once states with a majority of electoral votes join the pact.

According to NationalPopularVote.com, California, Connecticut, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, New York, Rhode Island, Vermont, Washington, and Washington, D.C. have passed a national popular vote bill.

The website says “the bill would guarantee the Presidency to the candidate who receives the most popular votes in all 50 states and the District of Columbia.”  

Jon Caldara, president of the Denver-based Independent Institute, questioned the constitutionality of the plan in previous comments to Watchdog.org.

“It is unclear whether this is constitutional, that will have to be hashed out in the courts,” Caldara said. “I just can’t figure out why our legislature wants our presidential electors to be beholden to forces outside of our state.”

Colorado News Editor

Derek Draplin covers Colorado for Watchdog.org. He previously worked as an opinion producer at Forbes, and as a reporter at Michigan Capitol Confidential and The Detroit News. He’s also an editor at The Daily Caller.