DENVER (AP) — Former Colorado Gov. John Hickenlooper won the Democratic nomination Tuesday to face Republican Sen. Cory Gardner in November, overcoming a series of stumbles and beating back a challenge from his left.

Hickenlooper's defeat of former Colorado House Speaker Andrew Romanoff was the second win by a centrist Democrat in a Senate primary Tuesday, after a late vote count from last week's Kentucky Senate primary gave Amy McGrath the win over State Rep. Charles Booker. Romanoff is a former moderate who turned himself into a populist, running against the moderate favorite of the Democratic establishment and promising a Green New Deal and single-payer health care.

But he could not overcome both Hickenlooper's immense financial edge — the former governor out-raised Romanoff by about 7-to-1 — and his deep name ID and reservoir of goodwill among voters stemming from two terms in the governor's mansion.

That's why Senate Democrats recruited Hickenlooper, 68, to take on Gardner, widely seen as the most vulnerable Republican in the Senate. Democrats need to net three seats in November to win control of the chamber if they win the White House, and they see Colorado as their most promising opportunity. Senate Democrats convinced Hickenlooper to run as his ill-fated bid for the Democratic presidential nomination fizzled last summer.

Hickenlooper's relatively easy win against Romanoff, Democrats argue, showed his resilience as a candidate whom Coloradans trust as a gaffe-prone, but authentic, leader.

“I've never lost an election in this state and I don’t intend to lose this one,” Hickenlooper said Tuesday night as he previewed his line of attack against Gardner: “We know what Donald Trump told us himself: Cory Gardner is with him 100% of the time.”

In an interview, Gardner previewed how he intends to fight back. In contrast to Hickenlooper's attempt to link the election to national issues like Trump, the coronavirus pandemic and collapsing economy, Gardner rattled off some of his recent accomplishments — luring the headquarters of U.S. Space Command and the Bureau of Land Management to Colorado and passing a sweeping public lands bill.

“I'm with the people of Colorado 100% of the time,” Gardner, 45, said.

The Republican Senator also called Hickenlooper “the most corrupt governor in the history of Colorado.” It was a reference to the state ethics commission finding in early June that Hickenlooper violated the state's ethics law by failing to reimburse for a private plane flight and limousine ride while he was governor. Hickenlooper had refused to testify during a virtual hearing, insisting on an in-person one, earning a contempt citation from the nonpartisan commission.

The ethics case was part of a miserable final stretch for Hickenlooper in June. Amid the protests over police violence against Black people, Hickenlooper garbled the meaning of the slogan “Black Lives Matter.” The following week, an African American Romanoff supporter tweeted a 6-year-old video of Hickenlooper jokingly comparing politicians to slaves being whipped to row “an ancient slave ship.”

The combination of the gaffes and setbacks was enough to lure Republicans to launch millions of dollars in ads attacking Hickenlooper. Democrats responded with defensive ads, and Romanoff then jumped in and added his own attack ad versus the former governor.

Colorado's Democratic establishment, from Gov. Jared Polis to Sen. Michael Bennet, condemned Romanoff for the move. Then, days later, a big-money group that will not disclose its donors launched a $1 million ad campaign slamming Romanoff for spearheading an anti-illegal immigrant bill in 2006. Romanoff has since apologized for the bill.

Republicans always expected Hickenlooper to win the primary, though many rooted for Romanoff and the GOP hopes that Hickenlooper has been banged up enough to give Gardner a chance in the November election.

But Colorado Democrats are eager to oust Gardner. Romanoff quickly called Hickenlooper to congratulate him on the victory after polls closed Tuesday evening. “For all the differences that we had, and there were many in this race, I am equally committed to making sure Cory Gardner is a one-term senator,” Romanoff told supporters during a virtual victory party on Zoom.

No Republican has won a statewide election in Colorado since 2014, when Gardner won by less than 2 percentage points in a strong year for Republicans. Hickenlooper was reelected as governor that year by a wider margin.