Story highlights The election was to replace Rep. Mike Pompeo, now the CIA director

Estes defeated Democrat Jim Thompson, a civil rights attorney and Army veteran

Washington (CNN) Republican Ron Estes, the state treasurer, has won a special election Tuesday night in Kansas to replace Rep. Mike Pompeo, who became President Donald Trump's CIA director, CNN projects.

Estes defeated Democrat Jim Thompson, a civil rights attorney and Army veteran, and Libertarian Chris Rockhold.

The seat was considered to be by Republicans a straight win -- until an energized Democratic base left Estes with a smaller advantage.

Trump tweeted about the race Tuesday morning, urging voters to get out and support Estes over his Democratic challenger.

"Ron Estes is running TODAY for Congress in the Great State of Kansas. A wonderful guy, I need his help on Healthcare & Tax Cuts (Reform)," Trump tweeted

Ron Estes is running TODAY for Congress in the Great State of Kansas. A wonderful guy, I need his help on Healthcare & Tax Cuts (Reform). — Donald J. Trump (@realDonaldTrump) April 11, 2017

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