Nevada Democrat Jacky Rosen is in a neck-and-neck battle in her bid to return to the U.S. Senate for a second term, while her party lost its slim voting majority in the upper chamber of Congress.

Democratic Sen. Jacky Rosen trailed Republican Sam Brown by less than 1,000 votes as Nevada counties stopped reporting results early Wednesday morning. As of Wednesday at 3 a.m., Brown led Rosen by 870 votes — or 0.

If Brown wins, it could expand Republicans' likely majority in the U.S. Senate. If Rosen wins, it could make controversial bills harder to pass.

Nevada Sen. Jacky Rosen was leading in Nevada’s Senate race against Republican candidate Sam Brown by about 6,000 votes Tuesday night.

A Republican group supporting Senate races says it will spend $6.2 million on TV, radio and digital ads beginning this weekend.

LAS VEGAS — In the swing state of Nevada, the U.S. Senate race and most House races were too early to call early Wednesday.

Nevada Democratic U.S. Sen. Jacky Rosen and Republican challenger Sam Brown were literally tied after initial election results were released Tuesday night, and by that time the race in Nevada was already irrelevant to control of the Senate,

Nevada Sen. Jacky Rosen was trailing Republican candidate Sam Brown by over 9,000 votes in the race for Nevada’s U.S. Senate seat Tuesday night. Brown received 48 percent of the vote to 47.2 percent for Rosen.