Sen. Cory Gardner, R-Co., is a first-term senator running for reelection in a state that is expected to be swept by a blue wave. Voters in the state are seemingly turning away from the Republican Party under President Trump.

Here’s what to know about Gardner:

He and his challenger have a history together

Gardner and his Democratic challenger, former Gov. John Hickenlooper, are no strangers to Colorado’s political scene and appeared on the same ballot during Gardner’s successful run for Senate in 2014.

While Hickenlooper was entering his second term as governor, Gardner moved from the House where he served two terms as Colorado’s Representative for the Fourth Congressional District, to the other side of the Capitol building, becoming the state’s junior senator.

Serving as Colorado’s top leaders for a decade meant that Hickenlooper and Gardner were long-standing acquaintances before their race for the Senate, but what was once a cordial -- if not friend-like relationship from across the aisle -- has turned bitter during a contentious race.

Congressional Democrats are looking to Gardner’s seat as an opportunity to flip a conservative holding in a rapidly blue-trending state, in order to try and gain a majority in the Senate.

Gardner’s history as a politician for Colorado

Gardner beat his Democratic opponent then-Sen. Mark Udall, a Democrat, by 2.5 percent, and flipped the seat back to Republican control. Prior to Udall’s one term as a senator, the seat was held by long-time Republican Sen. Ben Nighthorse Campbell from 1993-2005. Originally elected as a Democrat in 1993, Campbell defected to the Republican Party in March 1995.

Despite his 2015 win, Gardner has been trailing Hickenlooper in the state polls by 8.5 percent according to the most recent polling by Real Clear Politics – a trend that is likely attributable to his support of President Trump.

After the 2016 release of the infamous "Access Hollywood" tape where Trump alleged he sexually assaulted a woman, Gardner rescinded his endorsement and was highly critical of the presidential candidate.

“I will not vote for Donald Trump,” Gardner said in Oct. 2016.

“If Donald Trump wishes to defeat Hillary Clinton, he should do the only thing that will allow us to do so — step aside, and allow Mike Pence to be the Republican Party’s nominee. If he fails to do so, I will not vote for Hillary Clinton but will instead write-in my vote for Mike Pence,” he added.

But Gardner chose to endorse the president this time around and went so far as to answer “yes” when asked during a debate whether he thought Trump was moral and ethical.

But he added, “I wish he could be more specific in his communications with the American people.”

In 2019, the Lugar Center at Georgetown University rated Gardner as the third most “bipartisan” senator in Congress, but a separate report by FiveThirtyEight showed that Gardner had also voted favorably with the president 89% of the time over the last four years.

How Gardner’s change of heart on Supreme Court appointments likely hurt him in the polls

Gardner announced in late September that he would back Trump’s third nominee to the Supreme Court, following the death of the late Justice Ruth Bader Ginsburg – a move that greatly irritated Democrats and likely brushed moderate voters the wrong way, after the senator reversed his stance from 2016.

In 2016, Gardner sided with the then GOP-controlled Senate and refused to review President Obama’s nomination of Merrick Garland to the Supreme Court because it was an election year.

“[T]he next president of the United States should have the opportunity to fill the vacancy on the Supreme Court,” Gardner wrote in a press release in March of 2016.

“Our next election is too soon and the stakes are too high; the American people deserve a role in this process,” he added.

The decision to then back Trump’s appointment of Amy Coney Barrett to the Supreme Court just weeks before the general election likely led to his struggling poll numbers.

The Cook Political Report, changed their Nov. 3 projection of the Senate race, which is based on “qualitative and quantitative analysis,” from “toss-up” to “leans Democrat” after Gardner’s September announcement.

How Gardner tried to turn the tide in his race for re-election

Gardner in turn has tried to focus on drawing the line between him and Hickenlooper in the attempt to regain an edge against his Democratic challenger.

He has repeatedly pointed to Hickenlooper’s “ethical” violations that forced the former governor to pay a $2,750 fine after the state’s Independent Ethics Commission found that Hickenlooper had broken state laws by accepting “gifts” after being flown on a private jet several times during his governorship.

The senator has also pointed to Hickenlooper’s refusal to say whether or not he would “pack” the courts, along with his altered stance on fracking -- which the two-term governor was once an ardent supporter of. 

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But Gardner’s attempts to draw Hickenlooper as an inadequate and corrupt leader do not seem to have had much effect on the polling figures.

Over 2.5 million Coloradans have already cast their vote, meaning that over 88% of the total votes counted in the 2016 general election have already been returned, prior to the polls closing at 7 p.m. Tuesday, according to data from the United States Elections Project.