DENVER — Much is being made of the Republicans’ voter registration advantage in Colorado’s early voting, which inched from 104,000 Saturday to 106,000 on Sunday, seemingly a sign of yet another contested U.S. Senate battle tilting toward Republicans.

But election observers from Denver to Washington, DC would be wise to pay attention to another figure: that voter registration margin as a percentage of the overall vote.

As more votes come in, what was a 10-point GOP edge last week has slipped a little bit with each new early voting report from the Secretary of State, down to 9.2 percent Thursday, 9 percent Friday, 8.6 percent Saturday and now 7.9 percent Sunday.

As we’ve seen over several election cycles in Colorado, the early voter registration numbers can be deceiving; and the early Election Night returns often reflect few of the ballots cast over the final days of the race, offering little indication of how a race will end.

In 2010, Colorado Republicans went into Election Night feeling like that national GOP wave would still propel a stumbling Ken Buck past Democratic Sen. Michael Bennet, who finally claimed victory in the early morning hours the following day.

In 2012, Mitt Romney’s campaign believed it would win Colorado based on polling right up until the returns started coming in on Election Night.

In 2014, Republicans are again giddy about U.S. Senate candidate Cory Gardner’s chances to unseat Democratic Sen. Mark Udall — and with good reason: Gardner is arguably the best GOP Senate candidate in the country and has run a strong campaign in an already promising election year marked by broad Obama fatigue.

But with Udall’s campaign boasting the best Democratic ground game in the country, the race is far from in the bag.

Come Election Night, even if the first returns show Republicans leading, the question will be: by how much?

Because Democrats are almost guaranteed to make up significant ground as the night goes on and ballots cast over the final few days of the election are counted.

If the first returns show a Democratic candidate — Gov. John Hickenlooper, most likely — within a point or two of the Republican challenger, never mind leading, those races will be over early.

Heading into the final weekend, more than 1 million Coloradans had already voted; and 41 percent of them are Republicans compared to just 32 percent that are Democrats.

By Sunday morning, the margin narrowed slightly to 40-32, as Democratic voters outnumbered Republicans in a daily tally for the first time (35-32 percent).

It’s understandable why Democrats are nervous, and why national pundits see the race tilting toward Gardner.

That eight percent Republican advantage is significant, but politicos near and far would be wise to step outside of their emotions, beyond the prevailing media narrative and simply look at the numbers — and to remember that Democrats have a history of overcoming such margins with a surge of last-minute voters casting ballots on Election Day.

In 2010, Bennet overcame a six-point Republican advantage the day before Election Day to beat Buck by a percentage point. His victory wasn’t clear until after midnight on Election Day and he couldn’t claim victory until the following day.

Democrats are hoping — and, based on their own private polling, even cautiously optimistic — that the Udall-Gardner race may follow a similar script.

In short, they’re hoping for a late Election Night.

For whatever reason, Democratic voters tend to wait until the last minute to vote, whereas Republicans fill out their ballots and return them quickly.

“The first million votes cast tend to favor Republicans,” one Democratic operative explained. “The second million votes that come in are where we make up the ground.”

With Colorado’s new election law mandating that every registered voter receive a mail-in ballot, turnout this year is expected to top 2 million; that’s not presidential levels (2.6 million Coloradans voted in 2012) but better than 2010, when 1.8 million Coloradans cast ballots.

Of those 2 million or more votes, Democrats believe as many as 500,000 may be cast over the final two days of the election; and they think their best-in-the-nation ground game, which may knock on 500,000 doors over the final four days of the campaign, will help drive more Democrat-leaning voters to turn in their ballots ahead of Tuesday night’s 7 p.m. deadline.

So even if the voting numbers the Secretary of State puts out Monday still show a GOP advantage of 7-8 points, Democratic operatives won’t be overly worried, knowing those totals likely won’t include ballots received by clerks over the weekend that have yet to be processed.

Similarly, if the first dump of returns on Election Night shows Gardner ahead by 5-6 points, those attending the GOP’s watch party in Greenwood Village would be wise not to pop the champagne corks right then and there because that’s a margin Democrats believe they can still overcome.

Democrats seeing such a margin will likely spend the next several hours gnawing at their fingernails, but they may taste victory in the end.

Udall doesn’t even have to close the voter registration gap to zero in the end if he wins unaffiliated voters by a decent margin.

That said, if Gardner’s up by 8-10 points in the first dump of Election Night numbers, it might be time for Republicans to pop those corks — that would be a big margin for Udall to overcome.

In the governor’s race, Republican Bob Beauprez will be hoping that the early numbers have him up by about 4-5 points. Short of that, Gov. John Hickenlooper is likely headed for a second term.