WASHINGTON — Republicans seized control of the Senate and strengthened their hold on the House in a wave of Election Day victories Tuesday that served as a repudiation of President Barack Obama’s second-term policies and put a series of Democratic-leaning states — including Obama’s home, Illinois — under control of new Republican governors.

Senate Republican leader Mitch McConnell defeated Democrat Alison Lundergan Grimes in Kentucky, putting him in position to become the new Senate majority leader and confront Obama over his signature health care law.

Republicans took over formerly Democratic Senate seats in seven states, including GOP-leaning Arkansas, Montana, South Dakota and West Virginia. That number also included three states that figured prominently in Obama’s two victorious presidential campaigns: Iowa and Colorado, where he won twice, and North Carolina, where he won in 2008. Republicans needed a net gain of six seats in all to win back the majority for the first time since 2006.

“Thanks to you, Iowa, we are headed to Washington, and we are going to make them squeal,” declared Iowa Republican Joni Ernst, who vowed to cut pork in Washington in television ads that memorably cited her growing up castrating hogs.

In the House, Republicans were on track to meet or exceed the 246 seats they held during President Harry Truman’s administration over 60 years ago.

“We are humbled by the responsibility the American people have placed with us, but this is not a time for celebration,” said House Speaker John Boehner, R-Ohio. “It’s time for government to start getting results and implementing solutions to the challenges facing our country, starting with our still-struggling economy.”

In state capitols, Republicans were poised to leave their imprint, picking up governors’ seats in reliably Democratic states like Illinois, Maryland and Massachusetts. With Congress in gridlock, states have been at the forefront of efforts to raise the minimum wage and implement Obama’s health care law.

Many Republican governors seeking re-election had struggled with poor approval ratings but prevailed, including Florida Gov. Rick Scott, who defeated Democrat Charlie Crist, a former Republican governor; Kansas Gov. Sam Brownback; and Wisconsin Gov. Scott Walker, a potential GOP presidential candidate in 2016.

Voters expressed bitterness with a sluggish economic recovery and the nation’s handling of foreign crises. Nearly two-thirds of voters interviewed after casting ballots said the country was seriously on the wrong track. Only about 30 percent said the nation was headed in the right direction.

More than four in 10 voters disapproved of both Obama and Congress, according to the exit polls conducted for The Associated Press and the television networks.

Obama’s poor approval ratings turned him into a liability for Democrats seeking re-election. The outcome offered parallels to the sixth year of Republican George W. Bush’s presidency, when Democrats won sweeping victories amid voter discontent with the wars in Iraq and.

Democrats had few bright spots. New Hampshire Sen. Jeanne Shaheen and Gov. Maggie Hassan, who campaigned with potential 2016 candidate Hillary Rodham Clinton, both won re-election. In Pennsylvania, businessman Tom Wolf dispatched GOP Gov. Tom Corbett.