(AP) Republican Sen. Pat Toomey of Pennsylvania has narrowly defeated Democrat Katie McGinty in the most expensive political race in Senate history.

Republicans will retain control of the Senate after Toomey’s win in Pennsylvania if they hold Louisiana, Alaska as expected.

Toomey’s victory will keep Republicans in control of the Senate if GOP candidates in Alaska and Louisiana hold onto those seats, as expected.

Toomey, a former three-term congressman, was considered one of the most vulnerable Senate incumbents. A fiscal hawk, he was seeking a second term after compiling one of the most conservative voting records in Congress. Toomey tried to distance himself from Donald Trump as he appealed to moderate Democrats and independent voters willing to split their tickets, particularly in Philadelphia’s heavily populated suburbs.

McGinty, who has never held public office, was trying to become Pennsylvania’s first female senator. The 53-year-old worked in Bill Clinton’s White House and was recruited by top Washington Democrats to challenge Toomey.