With three weeks to go before election day and ballots already in the mail, campaign spending by Colorado candidates and the outside groups that back them is shifting to get-out-the-vote efforts.

And while Democratic candidates have far outpaced Republican opponents on campaign spending for the top ballot races, outside groups are narrowing that gap in at least some races, new campaign finance reports show.

Democratic gubernatorial candidate Jared Polis has spent $21.7 million, much of it his own, while the campaign for his Republican opponent, Walker Stapleton, having spent just over $1 million himself to date, has seen $5.9 million spent by outside groups to attack Polis or support Stapleton, the new reports show.

For other top state candidates, outside spending has nearly evened the playing field for Republicans in a year when Democrats’ fundraising and spending are strong.

In the attorney general’s race, for example, Democrat Phil Weiser has raised $2.4 million, compared with Republican George Brauchler’s $821,246. But the Republican Attorneys General Association has spent $3.5 million to support Brauchler. Its Democratic counterparts have spent just $146,821 to back Weiser.

The same is true in five key state Senate races. Democrats have raised and spent $1.124 million compared with the Republicans’ $197,118.But outside groups add more than $5 million to the Republicans’ spending; Democrats add about $3.7 million.

Overall, the most recent campaign finance reports from the Colorado secretary of state’s TRACER campaign finance system show more than $33 million has been spent in the 2018 election cycle by 46 independent expenditure committees. These committees are hoping to sway voters for governor, treasurer, secretary of state and attorney general, as well as the 17 Colorado state Senate and 65 House seats in play.

Funds are now being used to hire workers who can distribute door hangers and encourage their party’s voters to send in the ballots that should be showing up any day in most voters’ mailboxes.

Among the groups headed for Colorado streets and neighborhoods is Denver-based Work for Progress, which has been hired by outside spending groups that back Democrats, such as the Conservation Colorado Victory Fund and Colorado Fair Share Action.

Work for Progress took in more than $918,000 in the two-week reporting period between Sept. 27 and Oct. 10 for door-to-door voter contacts and literature drops alone. The group will also canvass on behalf of Polis and Democrats running for the state House and Senate.

Blitz Canvassing is among the groups working on get-out-the-vote efforts for Republican Senate candidates, primarily funded by outside spending committees like the Business Opportunity Fund and Colorado Advocates for Rural Electrification. Blitz received $240,000 between Sept. 27 and Oct. 10 for those activities.

That doesn’t mean mailers, TV, radio and internet ads are over by any stretch. Millions are still being spent by candidate campaigns and independent spending groups on ad buys.

One of the newest ads is from is Colorado Citizens for Truth, which hasn’t yet filed its first campaign finance report. However, a 48-hour notice, required for large expenditures, shows the committee spent $699,000 on an ad against Polis, the Boulder congressman.

The ad references a 1999 police incident involving Polis and a woman employee of his business that he thought was trying to steal documents. There was physical contact between the two. Polis called police, who investigated; they cited the woman for theft of trade secrets, to which she later pleaded guilty. Polis was not arrested or charged. (More details here.)

The Associated Press, in a “fact check” story, calls the ad misleading, as does KUSA-9News anchor Kyle Clark.

Checked on those claims about Jared Polis again today – yep, still inaccurate. pic.twitter.com/oOKODpUTjK

— Next with Kyle Clark (@nexton9news) October 16, 2018

The biggest dollars from independent expenditure groups (IECs) are, not surprisingly, committed to the governor’s race, with a dozen committees working exclusively in support of Polis or his Republican opponent, Stapleton, the state treasurer.

The most recent filings also show the largest ever expenditure by an IEC on behalf of secretary of state candidate Jena Griswold, a Democrat. Blueflower Action Fund, which backs Democratic women, put in $200,000 for an ad buy on Oct. 12.

Coloradans for Fairness, which backs Democrats for the state Senate, has raised the most of any outside spending group on behalf of candidates, with more than $5.4 million. Good Jobs Colorado, which backs Polis, has raised just over $5.1 million to date.

Among outside spending groups on the GOP side, Colorado Freedom, which is funded by the Republican Attorneys General Association, is the top fundraiser, with $3.5 million, followed by Better Colorado Now, with $3.25 million. The latter backs Stapleton.

Regarding direct candidate spending: More than $5.5 million was spent by candidate committees between Sept. 27 and Oct. 10, with $2.4 million spent by Polis for Colorado and $729,000 spent by Stapleton for Colorado.

Among the candidates themselves, Polis has now spent $21.7 million of his own money on his campaign, including $2 million he kicked in on Oct. 1. Stapleton’s total remains at $1.05 million with no new contributions since Sept. 17.

Here’s a roundup of candidate campaign spending for other statewide Colorado races through Oct. 10.

And here is spending on key state Senate races through Oct. 10.

Americans for Prosperity’s independent expenditure committee, in its finance report, cited two ad buys, at $107,000 and $108,000, but failed to disclose which candidates the ad buys support or oppose. The committee reported that spending as electioneering communications; the law requires the identification of targeted candidates.

AFP announced last month it would set up an outside spending group to support Stapleton, Neville and Jensen.

AFP-Colorado state director Jesse Mallory did not return a call for comment.