Republican state Treasurer Ron Estes, 60, will represent the Kansas 4th congressional district replacing Mike Pompeo, who Trump named as Central Intelligence Agency director. Pompeo cruised to re-election in November with 61 percent of the vote.

In what was supposed to be a give-away for the Republicans in the red state of Kansas, an nearly neck-and-neck race emerged in the early returns, which leaned toward Thompson. Unofficial final vote tallies show Estes scored a 7 percent victory over Thompson.

Republican Ron Estes says his victory in a special congressional election in Kansas shows that it remains a solid GOP state.

"Obviously, there's still work on the health care, to repeal and replace Obamacare (the Affordable Care Act)". We will have to beat them.

The second highest spender was Republican candidate Dan Moody, who spent $2 million in ads districtwide.

The Democratic Congressional Campaign Committee, the NRCC's counterpart, closely monitored the race and eventually did 25,000 live phone calls to get out the Democratic vote there. "When you have a governor hovering at about a 20 percent approval rating, and you supported that governor down the line, that's really hard to move away from". The seat, which Pompeo won with almost 61 percent of the vote in November, looked until recently like a lock for Estes, the state treasurer since 2011. He defeated James Thompson, the Democratic candidate, in the first national test of his party's electoral strength, in a contest that saw a late infusion of national support from Republicans nervous about the tumultuous political environment during President Trump's first months in office.

The civil rights attorney said he was inspired by Sen. Estes's percentage of victory exceeded that of Governor Brownback's margin in 2016 but fell far short of the majority racked up by President Trump. Democrat James Thompson kisses his wife Lisa while their daughter Liberty stands to their left at the Murdock Theatre in Wichita, Kan., Tuesday, April, 11, 2017. The 17-county congressional district includes the state's largest city of Wichita, home to Koch Industries, the company led by conservative billionaire political donors Charles and David Koch. If no one wins 50 percent, a runoff will be held in June.

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Estes claimed that the close election was proof that no Republican seat is safe, and vowed to campaign to retain his seat in 2018. "And we're going to make sure we change things in Washington".

"Republicans nationally should be very anxious", said Bob Beatty, a Washburn University political scientist.

Libertarian Gary Johnson received more than 55,000 votes in Kansas (4.7 percent) when he ran for president last fall.

Four-term U.S. Rep. Mick Mulvaney, R-Indian Land, resigned the 5th District seat in February to become Trump's budget director.

In November, Pompeo won reelection in the district by 32 percent, while President Donald Trump won the district by 27 percent.

"A wonderful guy", Trump tweeted about Estes on Tuesday. "It probably took all three to get Thompson this close".

We need to keep paying attention to special elections across the country, and progressives should not dismiss races that are in traditionally Republican areas.