What's the most expensive Senate race? Billions of dollars poured in for these candidates

Fernando Cervantes Jr., USA TODAY

Updated Fri, November 1, 2024 at 1:02 PM UTC

4 min read

With Election Day around the corner, hundreds of millions of dollars have been spent by candidates and outside groups across the U.S. vying to influence Senate races.

Democrats hold a thin majority in the Senate at 51-49. This year, 34 seats in the Senate are on the table, including a special election in Nebraska.

Ohio, Pennsylvania, Montana, Texas, and Michigan are among the most-watched races nationally, as they could flip the chamber from a Democratic majority to a Republican one. The Senate races are among the most expensive, all ranking within the top ten according to figures from OpenSecrets.

Here are the Senate races ranked from the most to least expensive.

The figures for the following ranking were sourced from OpenSecrets. Incumbent candidates are italicized with their party affiliation noted next to their name.

1. Ohio: Sherrod Brown (D) vs. Bernie Moreno (R)

Total money spent: $404,890,648
Money spent from outside groups: $283,545,814
What to know: Incumbent Sen. Sherrod Brown is running for his fourth term, holding his seat since 2007. Brown’s opponent is Ohio businessman Bernie Moreno, who had a failed Senate run in 2022.

2. Pennsylvania: Bob Casey (D) vs. Dave McCormick (R)

Total money spent: $289,130,166
Money spent from outside groups: $213,963,671
What to know: The same as Brown in Ohio, Casey is also running for his fourth term in the U.S. Senate. The Republican candidate in Pennsylvania is Dave McCormick, the former CEO of Bridgewater Associates, one of the world’s largest hedge funds.

Bob Casey (left) and Dave McCormick (right) candidates for U.S. Senate in Pennsylvania

3. Montana: Jon Tester (D) vs. Tim Sheehy (R)

Total money spent: $260,636,099
Money spent from outside groups: $155,501,692
What to know: Another third-term Senator running for another term, Democrat Jon Tester is challenged by Republican Tim Sheehy, a newcomer to Montana politics.

Jon Tester (left) and Tim Sheehy (right) are battling to win a seat in the United States Senate. Julia Nikhinson/REUTERS and Jasper Colt/USA TODAY NETWORK

4. Texas: Colin Allred (D) vs. Ted Cruz (R)

Total money spent: $199,454,872
Money spent from outside groups: $45,875,795
What to know: Republican two-term Sen. Ted Cruz is vying to win reelection in a state that has not elected a Democratic statewide candidate in almost three decades. His challenger, Democrat Colin Allred, is a current member of the House of Representatives and a former NFL player.

Colin Allred and Ted Cruz will debate Oct. 15 in their race for US Senate.

5. Michigan: Elissa Slotkin (D) vs. Mike Rogers (R)

Total money spent: $187,986,848
Money spent from outside groups: $124,424,764
What to know: In a race without an incumbent, Democrats and Republicans are jostling to claim the open Senate seat in Michigan. Elissa Slotkin is the current Representative for Michigan's 7th District, while the Republican candidate is Mike Rogers, the former Representative for Michigan's 8th District.

6. Wisconsin: Tammy Baldwin (D) vs. Eric Hovde (R)

Total money spent: $180,757,988
Money spent from outside groups: $105,485,993
What to know: Two-term Sen. Tammy Baldwin is running against Madison, Wisconsin, businessman Eric Hovde, who previously ran for the Senate in 2012. Hovde was defeated by former Gov. Tommy Thompson.

(Left) U.S. Sen. Tammy Baldwin (D-Wis) and (right) Republican U.S. Senate candidate Eric Hovde shake hands before the 2024 U.S. Senate Debate hosted by the Wisconsin Broadcasters Association Foundation on Friday October 18, 2024 at the WMTV-TV studios in Madison, Wis.

7. Nevada: Jacky Rosen (D) vs. Sam Brown (R)

Total money spent: $157,329,084
Money spent from outside groups: $92,673,749
What to know: Democrat Jacky Rosen is looking to win a second term in the Senate after winning her seat during the 2018 midterms. Her challenger is a Republican Sam Brown, who served in the Army during the Afghanistan War. He previously sought a seat in the Texas House of Representatives before moving to Nevada.

Jacky Rosen (left) and Sam Brown (right) the two candidates for Senate in Nevada.

8. Arizona: Ruben Gallego (D) vs. Kari Lake (R)

Total money spent: $156,049,777
Money spent from outside groups: $73,681,966
What to know: Both Gallego and Lake are vying to fill the seat left vacant by outgoing Sen. Kyrsten Sinema. Gallego is a current member of the House of Representatives while Lake is a former TV anchor and has had previous failed bids at elected office.

Arizona U.S. Senate candidates Rep. Ruben Gallego, D-Ariz., and Kari Lake answer questions during the Arizona Clean Election Commission debate at BitFire Studios in Phoenix on Oct. 9, 2024.

9. Maryland: Angela Alsobrooks (D) vs. Larry Hogan (R)

Total money spent: $146,298,442
Money spent from outside groups: $44,957,302
What to know: Angela Alsobrooks, the current County Executive for Prince George's County, is facing off against former Gov. Larry Hogan, a Republican, who served in the seat from 2015 to 2023.

Maryland candidates for U.S. Senator Angela Alsobrooks (D) and Larry Hogan (R).

10. California: Adam Schiff (D) vs. Steve Garvey (R)

Total money spent: $136,656,949
Money spent from outside groups: $22,382,214
What to know: Schiff and Garvey are both looking to fill the vacant Senate seat in California left by Sen. Diane Feinstein, who died in 2023. Schiff was the former chair of the House Intelligence Committee during his time in Congress, while Garvey is a former MLB player, winning the MVP Award for the National League in 1974 and a World Series championship with the Dodgers in 1981.