The congressman's win over the Democratic incumbent is critical for the GOP's majority hopes.
Uber's affiliate in Denver is offering discounted rates for voters heading to the polls.
Democrats Sen. Mark Udall and House hopeful Andrew Romanoff feel the heat.
Sen. Mark Udall (D-Colo.) hit for support of Obamacare and opposition to Keystone pipeline.
A push to ban the drilling technique could hurt Sen. Mark Udall's (D) reelection chances.
After winning GOP nomination, Ken Buck will likely succeed Rep. Cory Gardner.
Republicans predicted international and domestic benefits, while Democrats argued the benefits...
Tom Steyer's political action committee spent $65 million in these elections.
The first lady incorrectly identified Sen. Mark Udall (D) as "a fifth-generation Coloradan."
Democrat stood by his vote for ObamaCare while Gardner tacked to center on immigration.
GOP-aligned Crossroads GPS released an ad hitting Sen. Udall for his support of ObamaCare.
President heralds vulnerable senator as "serious person who's trying to do the right thing."
Six House Republicans who are running for Senate this year in competitive states voted for the...