A lot is riding on five local races that could flip the state Senate.

Colorado Democrats may be on the verge of ushering in a new progressive era in the state. If victorious, they could establish a political foothold for Democrats in the Mountain West region.

That’s just one reason why the race to control the Colorado Senate remains among the most closely watched state legislature battles in the whole country.

Democrats already control and House, and recent polling suggests they will maintain the governorship. If they flip the Senate, that would give Democrats a government trifecta for the first time in a decade.

And that could “dramatically change the landscape in terms of what state government can do,” says Colorado State University political professor Robert Duffy.

Specifically, winning the Senate would mean eliminating the GOP’s last backstop in terms of slowing down a progressive agenda.

For the last four years, Republicans have relentlessly, and narrowly, thwarted the Democratic agenda by killing lots of bills from the Democratic House that the Democratic governor likely would have signed into law: family paid leave, common sense gun reform, a minimum wage increase, a ban on gay conversion therapy, a new retirement savings system that would be accessible to all public- and private-sector employees, as well as a push to let voters choose whether to close offshore tax havens for large Colorado companies.

And this election cycle is highlighting a new type of Colorado Democrat, who is centrist and more activist. That’s why Sen. Bernie Sanders (I-VT) last week campaigned with Jared Polis, the Democratic nominee for governor.

Control of the Senate will likely come down to just five races, featuring five Democratic women candidates: Kerry Donovan, Tammy Story, Jessie Danielson, Brittany Pettersen, and Faith Winter. If at least four of the five women win, Democrats will likely run the Senate next year.

In terms of registered voters, Colorado remains nearly equally divided among Republicans and Democrats. But the state’s growing population is largely being driven by the arrival of new independent or unaffiliated voters, who often vote like Democrats. And Hillary Clinton won the state by five points in 2016.

Colorado independents, for most part, also disdain Trump, whose approval rating among that group in the state sits at an unappealing 32 percent.

Facing the prospect of a blue wave on Tuesday, Republicans have spent much of the campaign season on their heels, refusing to comment on whether they support Trump, while supporters for one arch-conservative Colorado Republican even faked an endorsements from the state’s current Democratic governor.

As has been the case for the entire year, Democrats continue to demolish their Republican counterparts when it comes to local fundraising.

In the five races that will likely determine the Colorado outcome, “The Democratic candidates in each have raised, in most cases, almost four times their Republican competitors, in some cases far more,” reports Colorado’s Daily Sentinel.

In the case of Democrat Kerry Donovan, she has outraised her Republican opponent 10-to-1.

Facing those odds, the GOP has been hoping all year that outside sources of deep-pocketed support can save them in terms of messaging. And those sources, driven largely by oil and gas concerns, have been dumping millions of dollars into the state.

Democrats have some major supporters as well. Just this week, the Sierra Club announced it was donating $65,000 to Faith Winter’s campaign.

“Faith has been a bold, thoughtful leader for protecting Colorado’s environment and creating jobs her entire career,” the Colorado Sierra Club, announced.

Colorado could soon become a true progressive outpost.