DENVER — Colorado’s Democrat-controlled Legislature on Thursday approved a bill to join other states in casting their presidential electoral votes for the winner of the national popular vote, and Gov. Jared Polis has said he will sign it.

Under the bill , Colorado would join 11 states and the District of Columbia in what’s called the National Popular Vote Interstate Compact. Currently, the state’s electoral votes are cast for whoever wins in Colorado.

The compact would kick in once enough states with a collective 270 electoral votes — the number needed to win the presidency — agree to join. The campaign was launched after Democrat Al Gore lost the 2000 election to Republican George W. Bush despite winning more votes.

Colorado Democrats introduced the bill after Donald Trump’s 2016 presidential victory over Democrat Hillary Clinton, who won 3 million more votes nationally.

The state House voted 34-29 Thursday to approve the bill, which had cleared the Senate.

Opponents say the initiative subverts an electoral college that was designed by the Founding Fathers to ensure, in part, that smaller states aren’t trampled over when it comes to choosing a president. They also insisted the matter should be put to the voters.

“Our founders feared the tyranny of the majority. In our electoral college our smaller states still have a say,” GOP Rep. Lori Saine warned before Thursday’s vote. “This is an exercise of the tyranny of the majority.”

“I hear time and again that my vote doesn’t count,” Democratic Rep. Emily Sirota, a bill co-sponsor, said of her constituents. “That’s the intention of this bill — to help people believe their vote matters.”

Currently, citizens voting for president are choosing electors from the political parties. The Electoral College has 538 electors, corresponding to the number of seats held by states in the U.S. Senate and House, plus three votes allotted to the District of Columbia.

Electors from compact states would pool their votes for the national popular vote winner — whether that candidate won in those individual states.

Compact members, including California (55 electoral votes) and New York (29), currently have 172 electors. Colorado, with nine, would give it 181.

Republican state lawmakers argued the compact would induce candidates to bypass smaller, rural, and often Republican-leaning states during their campaigns — and add Colorado, which voted overwhelmingly Democratic in the 2018 midterm elections, to that “flyover” territory.

Advocates said it would force the candidates to fight for votes in more states, including solidly red states like Texas and solidly blue states like California.

Those supporters include eight past chairs of the conservative American Legislative Exchange Council, which represents state lawmakers. Among other things, they argue the U.S. Constitution empowers the states to choose how they wish to elect a president. And that selection process has evolved within individual states over time.

Other compact members are Hawaii, Illinois, Maryland, Massachusetts, New Jersey, Rhode Island, Vermont and Washington.

Three other U.S. presidents were elected without winning the most votes: Rutherford B. Hayes (1876), Benjamin Harrison (1888) and John Quincy Adams (1824), who was voted into office by the U.S. House. Adams’ opponent, Andrew Jackson, had more electoral votes but not enough at the time to win outright.