Only 40 percent of registered Iowa voters approved of Governor Kim Reynolds’ work in the latest quarterly survey by Morning Consult, released on July 25. Some 39 percent of respondents disapproved and 21 percent didn’t know enough about Reynolds to have an opinion.

The findings suggest a noticeable slide in Reynolds’ net approval over the past six months. During the third quarter of 2017, Morning Consult found Reynolds was “off to a solid start, with an approval rating of 45 percent and a disapproval rating of 27 percent.” At that time, 30 percent of Iowa respondents didn’t know enough to have an opinion. The numbers from the fourth quarter of 2017 were little changed: 44 percent approve/29 percent disapprove/27 percent don’t know. Disapproval ticked up among Iowans surveyed from January through March, when the Republican-controlled legislature was in session, but the governor was still clearly in net positive territory: 42 percent approve/35 percent disapprove/23 percent don’t know.

Now, the difference between Reynolds’ approve and disapprove numbers is less than the Morning Consult poll’s 2 percent margin of error. As a general rule, any approval rating below 50 percent suggests an incumbent has reason to worry; 40 percent approval is well into the danger zone.

Before Democratic readers start celebrating, a few cautionary notes are in order:

• This poll had an unusually long survey window, from April 1 to June 30. Most opinion polls are in the field for less than a week.

• We don’t know whether Iowans became more supportive or less supportive of Reynolds’ work after she signed major legislation such as the near-total abortion ban or the costly Republican tax cut in May.

• With one-fifth of respondents not knowing enough about the governor to have an opinion, Reynolds has more room to grow her support than would a long-serving incumbent, about whom most voters have made up their minds.

• The Reynolds campaign began airing television commercials in Iowa’s largest media markets in April. She has spent around $2 million on tv advertising to date. We don’t know whether Iowans contacted by Morning Consult were more favorably inclined toward the governor later in the survey window, when more respondents would have been exposed to her positive biographical spots (see here, here, and here).

• The latest Morning Consult poll says nothing about how Iowans view Democratic nominee Fred Hubbell, or who leads a Reynolds/Hubbell matchup. Both campaigns have likely conducted internal polls since the June primary, but we may not see an independent poll of the governor’s race for some time. If the Des Moines Register sticks to past practice, the next Iowa poll by Selzer & Co will come out in mid- to late September.

Any relevant comments are welcome in this thread. Democratic candidates led the latest NBC/Marist polls of the governor’s races in Michigan, Minnesota, and Wisconsin.