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The 2020 Colorado Senate race is shaping up to be highly competitive as the Republican incumbent battles to hold his seat in a state that President Trump lost in 2016.

Sen. Cory Gardner will face off against Gov. John Hickenlooper, a Democrat. Here’s what to know:

Who are the candidates? 

Cory Gardner

Gardner won his Senate seat in 2014, narrowly beating Sen. Mark Udall. He is one of two Republican senators battling for reelection in a state that Trump lost, the other being Susan Collins from Maine.

In his reelection campaign Gardner has leaned on his work sponsoring the widely popular Great American Outdoors Act, a conservation bill that has passed both the House and Senate and Trump is likely to sign.

Despite Trump’s unpopularity in the state, Gardner has largely sided with the president, voting with him 90 percent of the time and campaigning with him in the 2020 Senate race.

(Gardner, right, Hickenlooper, leftGetty/AP)

HICKENLOOPER SEEKS TO OVERCOME UNFORCED ERRORS IN COLORADO SENATE RACE

Politico described him in 2019 as “reliably conservative on most issues other than immigration,” where he’s known to be more moderate. Last year, Gardner was among a small number of Republicans who supported a bipartisan compromise to provide citizenship to Dreamers, but that effort failed.

Gardner has also voiced a desire to do more to stop election interference by Russia. When asked if he’d want to repeal the Affordable Care Act, he’s said “Obamacare has failed,” but repealing it would be unlikely.

Many were angered when he endorsed Trump’s reelection. “People are surprised to find out that I’m a Republican,” Gardner said, when asked about the uproar.

“I believe in limited government, I believe in low taxes,” he added later. “If that makes me a conservative, that makes me a conservative.”

John Hickenlooper

Hickenlooper served as governor of Colorado from 2011 to 2019, when he unsuccessfully sought the 2020 Democratic nomination for the presidency. In a June 30 primary, Hickenlooper beat former state House Speaker Andrew Romanoff, his much more progressive rival.

The contest was closer than expected thanks to a few slip-ups by Hickenlooper, a one-time geologist turned brewpub owner.

In early June Hickenlooper was held in contempt by the Colorado Independent Ethics Commission after he didn’t appear at a mandatory hearing, defying orders to do so as the panel considers a Republican complaint that private plane trips he took while governor of Colorado violated the state's gift ban.

Mark Grueskin, an attorney for Hickenlooper, had logged onto the remote hearing 15 minutes after it started, citing problems with his Internet connection. Hickenlooper was also subpoenaed by the commission to appear but argued the hearing's remote format violates his right to face his accusers in person.

Hickenlooper was also forced to apologize when, during Black Lives Matter protests, a Denver school board member unearthed a video of him comparing the work of politicians to the work of enslaved people rowing a slave ship. He also came under fire from the left when in early June he struggled to define “Black Lives Matter” before saying the phrase meant “every life matters,” before later apologizing.

Race overview

The race is considered key in determining whether or not Republicans keep their majority in the Senate.

Gardner took a gamble endorsing President Trump, whose approval rating has gone down 16 points in the state since he took office. In 2019, Republicans lost a swing House seat in the Denver suburbs and Democrats captured the majority in the state legislature. Still, Gardner predicts the legislature’s liberal "overreach" will work in his favor.

Colorado Republican Rep. Doug Lamborn agrees. “He appeals to a lot of the unaffiliated voters,” said Lamborn. “He’ll run ahead of Trump." Colorado has more than 1.2 million people registered as unaffiliated, more than one third of the state’s electorate.

Gardner has classified Hickenlooper as “the most extreme-left” candidate Colorado Democrats have ever nominated.

“John Hickenlooper has no ideas of his own, other than Chuck Schumer’s talking points,” Gardner added, referring to the Senate minority leader from New York. “I vote 100 percent of the time for Colorado, and that is what I’m going to continue to do.”

Gardner has also hit the former governor for his alleged violations of state ethics law.

“If Hickenlooper wants to run a clean race then he should waive the statute of limitations and be honest about his trips on private jets and other ethics violations that were outside the statute of limitations,” Gardner said Tuesday. “Be honest with the people of Colorado. If he wants to be honest, be honest.”

Hickenlooper has sought to tie Gardner to Trump, and specifically his efforts to repeal the Affordable Care Act.

“There is a strong, strong recognition that Cory Gardner is part of what’s taking this country in the wrong direction,” Hickenlooper said in an interview with the Denver Post following his primary win.

“Throughout much of the primary campaign, I knew I wanted to unify the party eventually, after the primary. So we focused on Cory Gardner, on why he supports Trump’s lawsuit to get rid of the Affordable Care Act, on how in Colorado 2.4 million people have pre-existing medical conditions and will lose their protections if that lawsuit succeeds,” he added.

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Who has the edge? 

The nonpartisan Cook Political report rated the Colorado senate race a tossup and Sabato's Crystal Ball rated the race likely Democrat. Polling averages showed Hickenlooper beginning July with roughly an 11 point lead.