What is the most expensive Senate race?

Ohio tops the list with more than $400 million spent between the two candidates. More than a billion dollars have been spent in the top ten.

Of Election Day around the corner are hundreds of millions of dollars spent by candidates and outside groups in the US vying to influence Senate races.

The Democrats have a slim majority in the US Senate at 51-49. There are 34 Senate seats up for grabs this year, including a special election Nebraska.

Ohio, Pennsylvania, MontanaTexas and Michigan are among the most closely watched races nationally because they could flip the House from a Democratic majority to a Republican majority. The Senate races are among the most expensive and are all in the top ten figures from OpenSecrets.

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

The figures for the following rankings come from OpenSecrets. Incumbent candidates are in italics and their party affiliation is listed next to their names.

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

Total money spent: $404,890,648
Money spent by outside groups: $283,545,814
What you need to know: Incumbent Senator. Sherrod Brown is running for his fourth term and has held his seat since 2007. Brown’s opponent is Ohio businessman Bernie Moreno, who had an unsuccessful Senate run in 2022.

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

Total money spent: $289,130,166
Money spent by outside groups: $213,963,671
What you need to know: Same as Brown in Ohio, so is Casey run for his fourth term in the US Senate. The Republican candidate in Pennsylvania is Dave McCormick, the former CEO of Bridgewater Associates, one of the world’s largest hedge funds.

3. Montana: John Tester (D) vs. Tim Sheehy (right)

Total money spent: $260,636,099
Money spent by outside groups: $155,501,692
What you need to know: Another third term senator run for another term, Democrat John Tester is being challenged by Republican Tim Sheehy, a newcomer to Montana politics.

4. Texas: Colin Allred (G) vs. Ted Cruz (right)

Total money spent: $199,454,872
Money spent by outside groups: $45,875,795
What you need to know: Two-term Republican Sen. Ted Cruz is vying for reelection in a state that hasn’t elected a Democratic statewide candidate in nearly three decades. His challenger, Democrat Colin Allredis a current member of the House of Representatives and a former NFL player.

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

Total money spent: $187,986,848
Money spent by outside groups: $124,424,764
What you need to know: In a race without an incumbent, Democrats and Republicans are repress to claim Michigan’s open Senate seat. 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 (right)

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

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

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

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

Total money spent: $156,049,777
Money spent by outside groups: $73,681,966
What you need to know: Both Gallego and Lake are vying for the vacant seat of retiring Sen. Kyrsten Sinema. Gallego is a current member of the House of Representatives, while Lake is a former TV host and has previously had unsuccessful bids for elected office.

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

Total money spent: $146,298,442
Money spent by outside groups: $44,957,302
What you need to know: Angela Alsobrooks, the current County Executive of Prince George’s County, is running against former Gov. Larry Hogan, a Republican, who held the seat from 2015 to 2023.

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

Total money spent: $136,656,949
Money spent by outside groups: $22,382,214
What you need to know: Schiff and Garvey both want to fill the vacant California Senate seat left by Sen. Diane Feinstein, who died in 2023. Schiff was the former chairman 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.

Fernando Cervantes Jr. is a trending news reporter for USA TODAY. Reach him at [email protected] and follow him at X @fern_cerv_.