Fueled by popular discontent with Democratic President Barack Obama, Republicians took Senate control late Tuesday night, SIA reports quoting the AA.
Republican Mitch McConnell was the projected to win what was supposed to be a tightly contested race in Kentucky against Democratic challenger Alison Lundergan Grimes.
McConnell is slated to become Senate majority leader following the deluge of Republican victories.
In West Virginia, Republican Shelley Moore Capito is projected to defeat Republican Natalie Tennant. Capito was the first Republican to take a Senate seat in West Virginia in nearly 60 years. And in Arkansas, incumbent Democratic Sen. Mark Pryor is projected to fall to Republican challenger Tom Cotton.
Republicians also picked up seats in Colorado, North Carolina, Iowa, South Dakota and Montana.
They needed a net gain of six seats to wrest control of the chamber from Democrats.
A predicted runoff has been forced in Louisiana between Republican Bill Cassidy and Democratic Sen. Mary Landrieu. It is set for Dec. 6.
Republicians already had control of the House, and are widely expected to maintain it. With control of the Senate now assured, it will further complicate Obama's efforts to drive U.S. policy.
All 435 seats in the House of Representatives were up for grabs, while a little more than a third of Senate seats were contested. Each of the U.S.'s 50 states have two Senate seats.
Three dozen state governorships are also up for election.
A recent ABC News/Washington Post poll showed Obama’s favorability ratings hitting an all-time low. Just 44 percent of respondents said that they viewed the American president favorably.
The downward spiral in Obama’s popularity fueled the Republican charge to increase its hold in Congress, and led some Democrats running for office to distance themselves from the once-popular leader as they fought to gain or maintain their seat in highly competitive elections.
Chris Lowery, a resident of McLean, Virginia, said that Obama has not gotten enough credit for what he has accomplished, especially from his party.
“I feel the president isn’t getting enough credit – particularly other Democratic candidates aren’t recognizing him for what he has accomplished despite huge obstacles," he said. "Even if the Republicans prevail in controlling the Senate this time, I can't see how our nation is going to get anything meaningful done if Congress is basically at a standstill.
Before results were revealed, Annette Vaughan, a resident of neighboring Vienna said that while she hopes Republicians are able to gain control of the Senate, she was doubtful that it would actually result in the body, whose performance over the past two decades she said was "abysmal," passing needed legislation.
“I just think the president had an opportunity - and he had opportunities - to exert leadership,” she said. “I don’t think he did a very good job, and it’s time for another group to have a chance to do it.”
Turnout for midterm elections is generally lower than years in which presidential voting takes place. Roughly 40 percent of voters turn out for midterms compared to about 60 percent in presidential elections.