Republicans claimed the Senate majority Tuesday for the first time in eight years, riding President Barack Obama’s unpopularity to victories in every part of the country.

Republican challengers ousted Democratic senators in Arkansas, Colorado and North Carolina, and took seats from retiring Democrats in four other states. Equally important, Republicans held off spirited challengers in Kentucky, Georgia and Kansas, guaranteeing they will control both chambers of Congress for Obama’s final two years in office.

In every contested race, Republicans tied their opponents to the president, whose fortunes have sagged since his re-election two years ago. Democrats awkwardly tried to distance themselves from Obama without denouncing him.

Sen. Mitch McConnell of Kentucky, who won a sixth term Tuesday, was almost assured of being elected by his colleagues as majority leader, a lifelong dream. His party can send piles of legislation to Obama’s desk — for his signature or veto — on topics such as health care, environmental regulations and dozens of other issues.

McConnell immediately warned Obama of coming confrontations. “For too long, this administration has tried to tell the American people what’s good for them and then blame somebody else when their policies didn’t work out,” he told cheering fans.

The final Senate partisan breakdown won’t be known until Dec. 6, when Democratic Sen. Mary Landrieu of Louisiana will face Republican Rep. Bill Cassidy in a runoff. But the GOP’s majority was assured, regardless who wins there.

A GOP-run Senate will be an obvious aggravation to Obama and congressional Democrats, but it’s unclear how much it will change the government. Obama can veto bills, and Senate Democrats can use the filibuster to thwart scores of GOP initiatives, just as Republicans did to Democrats for years.

Republicans claimed a huge victory in Colorado, where GOP Rep. Cory Gardner ousted first-term Democrat Mark Udall. The win was notable because Obama had carried Colorado twice, unlike the other states where Republicans made their biggest gains.

Udall portrayed Gardner as a threat to women’s reproductive rights. But Gardner responded with the tactic used by every Republican in a competitive race: relentlessly linking his opponent to the president.

In North Carolina, state House speaker Thom Tillis ousted first-term Democratic Sen. Kay Hagan. She had accused him of leading a conservative revolution that went too far in the centrist state. Obama carried North Carolina in 2008, and lost it in 2012.

In Arkansas, freshman Rep. Tom Cotton knocked off two-term Democratic Sen. Mark Pryor in a state that has veered sharply toward the GOP since native son Bill Clinton left office.

Cotton, an Iraq combat veteran and Harvard Law School graduate, linked Pryor with Obama in every campaign appearance.

Pryor, the last Democrat in Arkansas’ congressional delegation, is the son of a popular former governor and senator. But Arkansas and West Virginia have been trending sharply Republican. Obama lost Arkansas by 24 percentage points in 2012.

As expected, GOP Rep. Shelley Moore Capito of West Virginia won the seat of retiring Democratic Sen. Jay Rockefeller. Former Gov. Mike Rounds of South Dakota won retiring Democratic Sen. Tim Johnson’s seat. And GOP Rep. Steve Daines will succeed departing Sen. John Walsh in Montana.

A rare bright spot for Democrats was Sen. Jeanne Shaheen’s victory in New Hampshire over Scott Brown, a former senator from Massachusetts.

In Georgia, where GOP Sen. Saxby Chambliss is retiring, Republican corporate executive David Perdue held off Democrat Michelle Nunn.

Kansas’ three-term Republican Sen. Pat Roberts avoided an embarrassing loss to independent candidate Greg Orman. Orman had persuaded the Democrat to leave the race and help him consolidate anti-Roberts sentiment.

In Virginia, Republican Ed Gillespie mounted an unexpectedly strong challenge to first-term Democratic Sen. Mark Warner.

Few campaigns were as feisty and close as Iowa’s, where longtime Democratic Sen. Tom Harkin is retiring. Republican state Sen. Joni Ernst defeated Democratic U.S. Rep. Bruce Braley in a race that featured TV ads about castrating hogs, and a leaked fundraising video from Texas.

First-term Democratic Sen. Mark Begich of Alaska faced Republican Dan Sullivan in a state Obama lost badly. A late vote count was possible there.

As Republicans awaited results elsewhere, they celebrated Sen. Tim Scott of South Carolina becoming the first black elected to the Senate from a former Confederate state since Reconstruction. He was appointed to the Senate last year, and won a term of his own Tuesday.

(AP)