BATON ROUGE, La. — Republican Rep. Bill Cassidy has denied Democratic Sen. Mary Landrieu of Louisiana a fourth term, calling his Senate victory "the exclamation point" on midterm elections that put Republicans in charge on Capitol Hill for President Barack Obama's last two years in office.
With nearly all votes counted, unofficial returns showed Cassidy with a commanding victory in Saturday's runoff as he ousted the last of the Senate's Deep South Democrats. In the South, Democrats will be left without a single U.S. senator or governor across nine states stretching from the Carolinas to Texas.
Cassidy, after a campaign spent largely linking Landrieu to Obama, called his win more of the same message American voters sent nationally on Nov. 4 as Republicans scored big gains in both chambers of Congress.
"This victory happened because people in Louisiana voted for a government that serves us, that does not tell us what to do," Cassidy said in Baton Rouge, the state capital.
He did not mention Obama or offer any specifics about his agenda in the Senate, but said in his victory speech that voters have demanded "a conservative direction" on health care, budgets and energy policy.
Following Cassidy's victory, Republicans will hold 54 seats when the Senate convenes in January, nine more than they have now.
Republican victories in two Louisiana House districts on Saturday — including the seat Cassidy now holds — ensure at least 246 seats, compared to 188 for Democrats, the largest GOP advantage since the Truman administration after World War II. An Arizona recount leaves one House race still outstanding.
Landrieu narrowly led a Nov. 4 Senate primary ballot that included eight candidates from all parties. But at 42 percent, she fell well below her marks in previous races and was sent into a one-month runoff campaign that Republicans dominated over the air waves.
The GOP sweep also denied former Louisiana Gov. Edwin Edwards a political comeback at age 87; the colorful politician who had served four terms as governor in the past had sought a return to public office after eight years in federal prison on corruption charges.
Landrieu hugged tearful supporters and sought to strike an upbeat chord Saturday night after her defeat. Her defeat was also a blow for one of Louisiana's most famous political families, leaving her brother, New Orleans Mayor Mitch Landrieu, to carry the banner.
"We may not have won tonight, but we have certainly won some extraordinary victories," she told supporters, citing her role in directing additional oil and gas royalties to Louisiana and securing federal aid after multiple hurricanes and the 2010 Gulf Oil Spill.
"It's been a fight worth waging," she said in New Orleans. She also said she was "proud" of her efforts to expand health care access, though she didn't specifically mention the Affordable Care Act.
The Louisiana race mirrored contests in other states this election season, with Landrieu, 59, joining Alaska Sen. Mark Begich, North Carolina Sen. Kay Hagan and Arkansas Sen. Mark Pryor in defeat. Democrats ceded seats in Montana, South Dakota and West Virginia after incumbents opted not to run again.
Like victorious Republicans in those races, Cassidy, a 57-year-old Illinois native, made his bid against Landrieu more about Obama than about his own vision for the job.
In a state where 73 percent of white voters on Nov. 4 told pollsters they "strongly disapproved" of the president, that was enough to prevent Landrieu from finding her footing as she tried several lines of attack.
Her anchor argument was that her seniority was a boon for Louisiana, particularly her chairmanship of the Senate's energy committee, an important panel for this oil-rich Gulf Coast state. But that argument was gutted Nov. 4 when Republicans won the Senate majority, meaning Landrieu would have lost her post even had she won.
The incumbent also had argued the race shouldn't be about Obama, but also targeted advertising on radio stations geared to the black community, where the president remains popular. And she hammered Cassidy as unfit for the job and more interested in partisanship than helping Louisiana.
Associated Press writer Stacey Plaisance contributed to this report from New Orleans. Barrow reported from Atlanta. Follow the reporters on Twitter @MDeslatte, @BillBarrowAP and @splaisance.