The Republicans have won control of the Senate in the US mid-term elections, increasing its power in the final two years of Barack Obama's presidency.
The party won in Arkansas, Colorado, Iowa, Montana, North Carolina, South Dakota and West Virginia, the BBC reported. It is expected to post more gains as votes are counted in other states.
Republican Senator Mitch McConnell, poised to lead the chamber, said the result was about "a government that people can no longer trust".
Throughout the campaign, Republicans focused on voter dissatisfaction with Mr Obama, a Democrat, describing the vote as a referendum on his presidency.
As the first results came in late on Tuesday, it became clear they had made convincing gains in the roughly one-third of the 100 Senate seats up for election.