Posted with permission from Newsweek

A Democrat resoundingly defeated her Republican rival to win the Wisconsin state Senate election Tuesday night, flipping a seat that had been red for nearly two decades—a possible harbinger of doom for the GOP in the coming midterm elections.

Patty Schachtner, the chief medical examiner in St. Croix County, beat state Representative Adam Jarchow by nine points just a little over a year after her Republican incumbent Sheila Harsdorf had held the seat with a  26-point re-election victory and President Donald Trump won district by 17 points over Hillary Clinton.

Harsdorf stepped down in November to serve as Governor Scott Walker's secretary of agriculture, causing the special election. 

Wisconsin Republicans suspected they would have trouble holding the seat, despite the 2016 success, given Trump's low approval ratings since taking office. Conservative groups spent over $130,000 on campaign ads for Jarchow—more than three times what Democratic groups spent to support Schachtner.

After Schachtner's historic upset, even Walker is warning Republicans not to take any seat for granted. 

"Senate District 10 special election win by a Democrat is a wake up call for Republicans in Wisconsin," Walker tweeted. 

Schachtner is just the latest Democrat to win a seat that had once been considered virtually unwinnable for the party. 

Last month, Doug Jones (D-Ala.) edged out Republican candidate Roy Moore, who had been accused of sexually assaulting and having inappropriate relationships with teenage girls as an adult, to become the first Democrat to represent Alabama in the Senate in more than 20 years. One month earlier in Virginia, Democrats grabbed at least 15 Republican seats in the House of Delegates. In that election, Democratic women defeated 11 male Republican incumbents, the first sign that the GOP may be in trouble in the 2018 midterm elections.

Schachtner insists there's no secret formula for flipping seats—she says voters are simply ready to hear a different message.

"People sent a message tonight we don't want to be negative any more," she told U.S. News. "Change it up. I ran a positive campaign. ... My message has always been be kind, be considerate and we need to help people when they're down."

Republicans are losing membership and support as the U.S. nears the crucial 2018 midterm elections, which may lead to Democrats regaining control of one, if not both, houses of Congress. Walker, for one, is sounding the alarm.

"[We] can't presume voters know that more people are working than ever before," Walker wrote Tuesday in a series of tweets. "[We] can't presume that voters know that we invested more actual dollars in schools than ever before. Help us share the good news."