Hillary Clinton’s campaign threw down nearly $500,000 on ads with Denver broadcast TV stations on Tuesday, with one week to go before the election.

The late ad buy has somewhat limited usefulness for the Democratic nominee at this point, with more than a million Colorado ballots already filled out an turned in.

Clinton’s campaign canceled a substantial amount of broadcast ads in Colorado this summer, when polling showed Clinton consistently ahead in the polls. She hasn’t advertised on KUSA since July.

Recent opinion polls in Colorado have trended closer, with some showing Republican Donald Trump within the margin of error.

In contrast with Clinton, Trump has run a heavy rotation of ads on Denver TV stations in recent months. He’s spent more than $4 million so far on broadcast ads in Colorado.

At this point, more than a third of the vote is likely in. 9NEWS political analyst Floyd Ciruli projects 2.8 million ballots may be cast this year.

However, the latest turnout data shows Colorado’s ever-crucial unaffiliated voters, who make up more than a third of the electorate, have been slower to get to the polls than voters registered with either major political party.

Democrats have outpaced Republicans in turnout so far, but the gap between them has narrowed. As of Tuesday, 37 percent of the ballots cast came from Democrats, 35 percent from Republicans, and 28 percent from independent of minor party voters.