U.S. Rep. Jacky Rosen greets supporters during a canvass launch at the Nevada State Democratic Party's Centennial Hills field office during midterm Election Day in Las Vegas, Nevada, U.S., November 6, 2018. REUTERS/Eric Thayer

(Reuters) - Democratic U.S. Representative Jacky Rosen unseated Nevada’s sitting U.S. senator, Republican Dean Heller, in one of the country’s closest election contests, data provider DDHQ and CNN projected on Wednesday.