Roll Call has this list of 7 Republican Senators Most Vulnerable in a Primary:
1. Mike Enzi, Wyoming
2. Mitch McConnell, Kentucky
3. Thad Cochran, Mississippi
4. Lindsey Graham, South Carolina
5. Pat Roberts, Kansas
6. Lamar Alexander, Tennessee
7. John Cornyn, Texas
Graham has 3 primary opponents already in Lee Bright, Richard Cash, and Nancy Mace. Bill Connor is also reportedly considering a run in the primary.
Quinton is a native South Carolinian who has lived in Baltimore since 2006. He is a recent convert to the Catholic Church and is active in the Knights of Columbus. He has been involved in the pro-life movement nationally and locally since 2010.
Quinton is a veteran who served as an intelligence analyst in the Army National Guard. He is also an Eagle Scout.