Sen. Claire McCaskill's (D., Mo.) net approval rating dipped by nearly 10 points in the past year, making her the least popular Democrat running for reelection in a state carried by Republicans in 2016, according to new polling data from Morning Consult.
At the beginning of 2017 McCaskill was viewed positively by 47 percent of Missouri voters and negatively by 39 percent, but she lost support throughout the year, according to the poll. By the end of the year, McCaskill's net approval had fallen by eight points, with both her positive and negative ratings sitting at 41 percent.
The Morning Consult data, taken quarterly for each U.S. senator, shows that McCaskill's approval fell throughout the year. In July her approval rating was 46-38 and by October it had dipped to 42-39.
The drop in approval rating was seen across the board for Democrats running for reelection in 2018. The biggest drop was for Sen. Bob Menendez (D., N.J.), who spent much of the year in federal court defending himself from corruption charges and saw a 20 point negative swing.
Also facing a drop in net approval was Indiana's Joe Donnelly (6 points), Montana's Jon Tester (18 points), West Virginia's Joe Manchin (8 points), North Dakota's Heidi Heitkamp (11 points), Ohio's Sherrod Brown (4 points), Wisconsin's Tammy Baldwin (6 points), and Pennsylvania's Bob Casey (9 points).
Menendez is the only senator up for reelection who is viewed negatively by voters.