Trump’s net approval rating was 13 points underwater, a 4 point decline from February.

Biggest drop was in Iowa — a net swing of 9 points from the previous month.

The month of March was unkind to President Donald Trump’s popularity among the voting public, with Morning Consult’s 50 state approval tracker showing the commander in chief reaching the lowest point of his presidency. The new data — compiled from surveys conducted March 1 to March 31 among 97,693 registered voters in every state and Washington, D.C. — shows 41 percent of registered voters approving and 54 percent disapproving of Trump’s job performance, surpassing previous monthly lows from October and November, when 42 percent approved and 53 percent took the opposing view. (Methodology for Morning Consult’s Tracking Trump feature available here.)

The new figures represent a 4 point net decline from February, when 43 percent approved and 52 percent disapproved of Trump. The changes were driven mainly by a loss of enthusiasm among the president’s independent and Republican supporters: Strong approval for Trump was down 2 points among GOP voters, to 45 percent, and 1 point among independents, to 13 percent.

At the state level, some of the biggest negative swings in net approval came from places that backed Trump in the 2016 presidential election: Iowa (minus 9 percentage points), Idaho and Tennessee (minus 6 points), and Montana and Oklahoma (minus 5 points). On the positive side, Trump made a 6 point gain in New Hampshire and improved his standing in West Virginia and Vermont by 4 points. Along with Sens. Joe Manchin (D-W.Va.) and Jon Tester (D-Mont.), who are seeking re-election in November, other Senate Democrats defending seats in Trump-won states also saw mixed results in terms of the president’s approval ratings. In Ohio, Trump dipped into the red, posting a 5 point loss in net approval since February, while falling 3 points deeper into the hole in Pennsylvania and Wisconsin — to minus 8 points and minus 12 points, respectively — and dropping the same amount in Michigan, to minus 13. In West Virginia, Trump sports a 26 point net approval rating, and in North Dakota he improved to 10 points above water.