During a town hall in October 2019, Iowa resident Amy Haskins asks Sen. Joni Ernst: “Where is the line?” when it comes to standing up to Trump. Ernst responds, “The president is going to say what the president if going to do…I can’t speak for him.” — CSPAN/video still

Sen. Joni Ernst’s approval rating among Iowans has dropped 10 percentage points over the last year, according to a new Iowa Poll. In the poll published by the Des Moines Register on March 7, only 47 percent of respondents said they approved of the job Ernst is doing as senator.

The February 2019 Iowa Poll marked Ernst’s highest point of approval, with 57 percent of respondents saying she was doing a good job.

Approval ratings below 50 percent during an election year usually indicate an incumbent will have a hard time winning reelection.

Ernst still has strong support among Iowa Republicans, 79 percent of whom approved of her performance in their poll response. But only 45 percent of independents and 14 percent of Democrats told pollsters they approved of her actions.

In addition to Republicans, Ernst received strong approval ratings from self-identified evangelicals (64 percent) and rural residents (61 percent). A majority of men — 53 percent — approved of Ernst’s performance in office, but only 42 percent of women did.

The new poll also found that people’s view of Ernst as a person has declined by 10 percentage points since last year. In February 2019, 56 percent of respondents said they had favorable opinion of Ernst. That dropped to 46 percent in the new poll. The number of people who said they had an unfavorable view of Ernst went from 29 percent to 36 percent.

Ernst does have certain advantages in her reelection bid. Iowans tend to vote for incumbents. (Democrats Tom Miller and Michael Fitzgerald are the longest-serving attorney general and state treasurer, respectively, in the country. Republican Terry Branstad was the longest-serving governor in American history, and Chuck Grassley has been in elective office continually since 1959.) Ernst also isn’t facing a primary challenger for the Republican nomination.

More importantly, the new Iowa Poll found the five Democrats running to challenge Ernst in the November election have almost no statewide name recognition. Only 27 percent of likely voters said they knew enough about Theresa Greenfield, the candidate with the backing of the Democratic Senate Campaign Committee, to form an opinion about her.

The other four Democratic candidates — Kimberly Graham, Eddie Mauro, Michael Franken and Cal Woods — were even less well known to likely voters.

Forty-one percent of the respondents who described themselves as “likely voters” in the general election said they would “definitely vote to reelect” Ernst, while 51 percent said they would either definitely vote for someone else or at least consider voting for another candidate.

The March 2-5 poll was conducted for the Des Moines Register and Mediacom by Selzer & Co., who surveyed 800 Iowa adults, 667 of whom were described as likely voters. The margin of error is plus or minus 3.5 percent for questions asked to all 800, and plus or minus 3.8 percent for the questions asked of just likely voters.