U.S. Senate hopeful Dave McCormick announced that his campaign raised $5.4 million during the last quarter of 2023 in his quest for the Republican nomination.

The former Bridgewater Associates CEO also added $1 million of his own to make the total among the largest quarters ever for a Republican challenger.

The campaign reported that more than 15,000 individual donors contributed to both “Friends of Dave McCormick,” the campaign committee, and “Team McCormick,” the joint fundraising committee, as well as a $1 million personal investment from McCormick.

The $6.4M total is another sign that Pennsylvania’s Senate race will be among the nation’s most competitive contests in November, with control of the U.S. Senate potentially hanging in the balance.

“Dave McCormick has earned the support of Pennsylvanians from all walks of life because they believe he is the kind of leader who can address the burden of inflation on working families, push for a secure border, and protect the security of Americans at home and abroad,” said campaign manager Matt Gruda. “A seventh-generation Pennsylvanian, West Point graduate, and Pennsylvania job creator, Dave is exactly the kind of candidate who can beat Bob Casey in November, shake up Washington, and get this country back on track from the failed policies of Joe Biden.”

McCormick has been endorsed by the entire Pennsylvania GOP congressional delegation, which could help him avoid the kind of nasty primary that left Trump-backed TV personality Mehmet Oz bruised before the 2022 general election, which he lost to Sen. John Fetterman (D-Pa.).

Casey, the three-term incumbent, has yet to announce a Q4 total but brought in more than $4M in the second quarter and $3.2M in the third.

Quarterly fundraising reports for the fourth quarter are due to the Federal Election Commission by January 31, but some candidates — such as McCormick, who began his campaign in September — announce their fundraising figures ahead of time, especially when they’re pleased with their numbers.