Polls in Colorado have closed. Follow for live results on giving the state's electoral votes to the winner of the US popular vote

• Colorado is voting on Proposition 113, which will determine whether the state and its nine electoral college votes will join the National Popular Vote Interstate Compact.
• Polls in Colorado closed at 9 p.m. ET.
• States in the compact pledge to give all their electoral college votes to the nationwide winner of the presidential popular vote — regardless of which candidate wins their own state.
• If the measure passes and Colorado enters, jurisdictions representing 196 electoral votes will be in the compact. The compact goes into effect and has legal force once states representing a total of 270 votes join.

Tonight, Colorado residents will vote on Proposition 113, which will determine whether the state and its nine electoral college votes will join the National Popular Vote Interstate Compact, a group of states that pledge all their electoral college votes to the winner of the popular vote.

Polls in Colorado closed at 9 p.m. ET.

Colorado's state legislature enacted a bill to enter the state into the compact that hasn't gone into effect yet, pending the outcome of Proposition 113. If the measure passes, Colorado will be the first state where voters directly vote to enter the college into the compact.

Every state except Maine and Nebraska uses a "winner take all" system that pledges all the state's electoral college votes to the candidate that earns more than 50% of the vote. A presidential candidate needs a majority of 270 electoral college votes to win.

In the past 20 years, the "winner take all" structure of the Electoral College has come under scrutiny after Presidents George W. Bush and Donald Trump were elected by the Electoral College despite losing the popular vote.

Abolishing the electoral college itself would require a constitutional amendment, which is unlikely to happen anytime in the near future. So individual states have found a workaround to, in their view, make the electoral college more representative of the popular vote.

Since 2007, 16 states and the District of Columbia have joined the Compact, in which member states pledge to give all their electoral college votes to the nationwide winner of the presidential popular vote — regardless of which candidate wins their own state.

The states already in the compact hold a total of 196 electoral votes (including those belonging to Colorado), a little less than three-fourths of the 270 Electoral College votes needed for the compact to take effect. If this goal is reached, the compact will also hold legal weight.

The text of the proposition as it appears on the ballot:

"Shall the following Act of the General Assembly be approved: An Act concerning adoption of an agreement among the states to elect the President of the United States by national popular vote, being Senate Bill No. 19-042?"