- Joe Manchin III Senator from WV, Independent
- Edward J. Markey Senator from MA, Democratic
- Roger Marshall Senator from KS, Republican
- Mitch McConnell Senator from KY, Republican
- Robert Menendez Senator from NJ, Democratic
- Jeff Merkley Senator from OR, Democratic
- Jerry Moran Senator from KS, Republican
- Markwayne Mullin Senator from OK, Republican
- Lisa Murkowski Senator from AK, Republican
- Christopher Murphy Senator from CT, Democratic
- Patty Murray Senator from WA, Democratic
- Jon Ossoff Senator from GA, Democratic
- Alex Padilla Senator from CA, Democratic
- Rand Paul Senator from KY, Republican
- Gary C. Peters Senator from MI, Democratic
- Jack Reed Senator from RI, Democratic
- Pete Ricketts Senator from NE, Republican
- James E. Risch Senator from ID, Republican
- Mitt Romney Senator from UT, Republican
- Jacky Rosen Senator from NV, Democratic