A Handy Crash Course in Which Senators Are Up, and When?

United States senators are elected to six-year terms. The entire Senate is divided into three different classes. Each of these classes is made up of 33 or 34 Senate seats each.

The reason for the three classes is to determine which seats are up for election in any given year, and to ensure that a third of the Senate must face the voters every two years.

This excludes any special elections or appointments, which is why we are seeing both Georgia Senate seats (Senators Kelly Loeffler and Mark Perdue) up this November

Article I, Section 3 of the Constitution mandates the Senate’s class structure.

The Senate of the United States shall be composed of two Senators from each State, chosen by the Legislature thereof, for six Years; and each Senator shall have one Vote.

Immediately after they shall be assembled in Consequence of the first Election, they shall be divided as equally as may be into three Classes. The Seats of the Senators of the first Class shall be vacated at the Expiration of the second Year, of the second Class at the Expiration of the fourth Year, and of the third Class at the Expiration of the sixth Year, so that one third may be chosen every second Year; and if Vacancies happen by Resignation, or otherwise, during the Recess of the Legislature of any State, the Executive thereof may make temporary Appointments until the next Meeting of the Legislature, which shall then fill such Vacancies.

The current make-up of the Senate is as follows:
Republicans have 53 seats
Democrats have 45 seats
Independents have 2 seats
…for a total of 100

Under the Constitution, the vice-president serves as president of the Senate. He or she may vote in the Senate in the case of a tie, but is not required to do so.

WHO ARE THE CLASS II SENATORS?

We’ll start with Class II Senators because they’re all up for re-election this November. If you are a CLASS II Senator, you were elected in the 2014 election, excluding any appointments or special elections. Your term runs from January 3, 2015 until the end of the 116^th Congress on January 3, 2021

Senator David Perdue of Georgia is at the end of his term, and up for re-election. However, because Kelly Loeffler of Georgia was appointed to the other state’s other seat by Governor Brian Kemp, she is also up this November. Whoever wins that race will complete the resigned Senator Johnny Isakson’s original term, which runs until January 2023.

Here are your Class II Senators

Democrats

Booker, Cory A. (D-NJ)

Coons, Christopher A. (D-DE)

Durbin, Richard J. (D-IL)

Jones, Doug (D-AL)

Markey, Edward J. (D-MA)

Merkley, Jeff (D-OR)

Peters, Gary C. (D-MI)

Reed, Jack (D-RI)

Shaheen, Jeanne (D-NH)

Smith, Tina (D-MN)

Udall, Tom (D-NM)

Warner, Mark R. (D-VA)

Republicans

Alexander, Lamar (R-TN)

Capito, Shelley Moore (R-WV)

Cassidy, Bill (R-LA)

Collins, Susan M. (R-ME)

Cornyn, John (R-TX)

Cotton, Tom (R-AR)

Daines, Steve (R-MT)

Enzi, Michael B. (R-WY)

Ernst, Joni (R-IA)

Gardner, Cory (R-CO)

Graham, Lindsey (R-SC)

Hyde-Smith, Cindy (R-MS)

Inhofe, James M. (R-OK)

McConnell, Mitch (R-KY)

Perdue, David (R-GA)

Risch, James E. (R-ID)

Roberts, Pat (R-KS)

Rounds, Mike (R-SD)

Sasse, Ben (R-NE)

Sullivan, Dan (R-AK)

WHO ARE THE CLASS III SENATORS?

These are the Senators who will be up in the 2022 mid-term elections.

If you are a Class III Senator, you were elected in the 2016 election and your term runs from January 3, 2017 until the end of the 115^th Congress on January 3 2023.

Here are your Class III Senators

Democrats

Bennet, Michael F. (D-CO)

Blumenthal, Richard (D-CT)

Cortez Masto, Catherine (D-NV)

Duckworth, Tammy (D-IL)

Harris, Kamala D. (D-CA)

Hassan, Margaret Wood (D-NH)

Leahy, Patrick J. (D-VT)

Murray, Patty (D-WA)

Schatz, Brian (D-HI)

Schumer, Charles E. (D-NY)

Van Hollen, Chris (D-MD)

Wyden, Ron (D-OR)

Republicans

Blunt, Roy (R-MO)

Boozman, John (R-AR)

Burr, Richard (R-NC)

Crapo, Mike (R-ID)

Grassley, Chuck (R-IA)

Hoeven, John (R-ND)

Johnson, Ron (R-WI)

Kennedy, John (R-LA)

Lankford, James (R-OK)

Lee, Mike (R-UT)

Loeffler, Kelly (R-GA)

McSally, Martha (R-AZ)

Moran, Jerry (R-KS)

Murkowski, Lisa (R-AK)

Paul, Rand (R-KY)

Portman, Rob (R-OH)

Rubio, Marco (R-FL)

Scott, Tim (R-SC)

Shelby, Richard C. (R-AL)

Thune, John (R-SD)

Toomey, Patrick J. (R-PA)

Young, Todd (R-IN)

WHO ARE THE CLASS I SENATORS?

If you are a CLASS I Senator, you were elected to office in November of 2018. Your term will run from January 3, 2019 until the end of the 118^th Congress on January 2, 2025

Here are your Class I Senators

Democrats

Baldwin, Tammy (D-WI)

Brown, Sherrod (D-OH)

Cantwell, Maria (D-WA)

Cardin, Benjamin L. (D-MD)

Carper, Thomas R. (D-DE)

Casey, Robert P., Jr. (D-PA)

Feinstein, Dianne (D-CA)

Gillibrand, Kirsten E. (D-NY)

Heinrich, Martin (D-NM)

Hirono, Mazie K. (D-HI)

Kaine, Tim (D-VA)

Klobuchar, Amy (D-MN)