(NewsNation) — The balance of power could shift in both chambers of Congress on Election Day, led by several toss-up races that could determine which party holds power in the federal legislature. See the results of the presidential election here.
A total of 34 U.S. Senate seats will be determined on Election Day, with Democrats and Independents representing 23 of those races. Democrats are vying to hold on to the slim majority they have held in the upper chamber of Congress for the past two years. Some of the seats they will defend are in tougher-to-hold battleground states, including Arizona, Florida, Michigan, Pennsylvania and Wisconsin.
Meanwhile, Republicans hold a narrow majority in the U.S. House of Representatives with 220 seats over the Democrats who held 212 and three seats being vacant into Tuesday’s election. While there were hundreds of races, just a tenth of the races were deemed competitive, according to the Cook Political Report.
Twenty-five were considered toss-ups with 11 of the seats held by Democrats and 14 by Republicans, and 17 races were rated as either leaning Democratic or leaning Republican.
Balance of Power in US House and US Senate
Key US Senate races to watch
The balance of power in the U.S. Senate will likely be determined by the outcome of these races:
Arizona: Democrat U.S. Rep. Ruben Gallego vs. Republican Kari Lake
Florida: Republican U.S. Sen. Rick Scott vs. Democrat Debbie Mucarsel-Powell
Maryland: Democrat Angela Alsobrooks vs Republican Larry Hogan
Michigan: Democrat Elissa Slotkin vs. Republican Mike Rogers
Missouri: Republican U.S. Sen. Josh Hawley vs. Democrat Lucas Kunce
Montana: Democrat U.S. Sen. Jon Tester vs. Republican Tim Sheehy
Nevada: Democrat U.S. Sen. Jacky Rosen vs. Republican Sam Brown
New Mexico: Democrat U.S. Sen. Martin Heinrich vs Republican Nella Domenici
West Virginia: Republican Gov. Jim Justice vs. Democrat Glenn Elliott
Wisconsin: Democrat U.S. Sen. Tammy Baldwin vs. Republican Eric Hovde
Key US House races to watch
Here are the races expected to make a difference in the U.S. House of Representatives:
Alaska: Democrat U.S. Rep. Mary Peltola vs. Republican Nick Begich
Arizona District 1: Republican U.S. Rep. David Schweikert vs. Democrat Amish Shah
California District 13: Republican U.S. Rep John Duarte vs. Democrat Adam Gray
California District 22: Republican U.S. Rep. David Valadao vs. Democrat Rudy Salas
California District 27: Republican U.S. Rep. Mike Garcia vs. Democrat George Whitesides
California District 41: Republican U.S. Rep. Ken Calvert vs. Democrat Will Rollins
California District 45: Republican U.S. Rep. Michelle Steel vs. Democrat Derek Tran
Colorado District 8: Democrat U.S. Rep. Yadira Caraveo vs. Republican Gabe Evans
Iowa District 3: Republican U.S. Rep. Zach Nunn vs. Democrat Lanon Baccam
Maine District 2: Democrat U.S. Rep. Jared Golden vs. Republican Austin Theriault
Michigan District 7: Democrat Curtis Hertel, Jr. vs. Republican Tom Barrett
Michigan District 8: Democrat Kristen McDonald Rivet vs. Republican Paul Junge
Nebraska District 2: Republican U.S. Rep. Don Bacon vs. Democrat Tony Vargas
New Mexico District 2: Democrat U.S. Rep. Gabe Vasquez vs.Republican Yvette Herrell
New York District 4: Republican U.S. Rep. Anthony D’Esposito vs. Democrat Laura Gillen
New York District 17: Republican U.S. Rep. Mike Lawler vs. Democrat Mondaire Jones
New York District 19: Republican U.S. Rep. Marc Molinaro vs. Democrat Josh Riley
North Carolina District 1: Democrat U.S. Rep. Don Davis vs. Republican Laurie Buckhout
Ohio District 13: Democrat U.S. Rep. Emilia Sykes vs. Republican Kevin Coughlin
Oregon District 5: Republican U.S. Rep. Lori Chavez-DeRemer vs. Democrat Janelle Bynum
Pennsylvania District 7: Democrat U.S. Rep. Susan Wild vs. Republican Ryan Mackenzie
Pennsylvania District 8: Democrat U.S. Rep. Matt Cartwright vs. Republican Rob Bresnahan
Virginia District 7: Democrat Eugene Vindman vs. Republican Derrick Anderson
Washington District 3: Democrat U.S. Rep. Marie Gluesenkamp Perez vs. Republican Joe Kent
NewsNation’s Safia Samee Ali contributed to this story.