Sen. Claire McCaskill (D., Mo.) called President Donald Trump's tenure to date a "work in progress" as she fights to keep her seat in one of the nation's most closely watched races.
Seeking a third term in a state Trump won handily in 2016, McCaskill has sought to cast herself as a pragmatic, independent voice in the chamber.
According to FiveThirtyEight, she has voted with Trump about 45 percent of the time. She's opposed several major Trump initiatives, including both his Supreme Court nominees, the Republican tax reform bill, and a skinny repeal of the Affordable Care Act.
"I don't do a knee-jerk opposition to the president," she told "CBS Evening News" anchor Jeff Glor. "I try to figure out each nomination and each policy position based on the merits, and then I have to explain it to Missourians."
"But would you call his presidency a success?" Glor asked.
"I think it's a work in progress, and I think that's up to voters," she said.
Her opponent, Republican Missouri Attorney General Josh Hawley, is running neck-and-neck with her in the polls. The latest RealClearPolitics average of polling shows him holding an advantage of less than half a percentage point.
He portrays McCaskill as a tool of Senate Minority Leader Chuck Schumer (D., N.Y.) who doesn't properly represent the state.
An ally of Trump, Hawley said he would tell him to keep a "hard line on spending" and criticized Congress for being too reckless with the purse.
Holding onto the seat is crucial for Democratic hopes of taking back the Senate chamber. Should McCaskill lose, it will be nearly impossible for Democrats to defeat enough Republican incumbents to win the majority for the first time in six years.