On Tuesday, Donald Trump hit a new, unhappy milestone in his time as president. For the first time, the percentage of the country that disapproves of his job performance in Gallup’s daily rating hit 60 percent.

If long-term trends continue, it won’t be the last time, either.

As historian Kevin Kruse noted on Twitter, that’s a higher disapproval rating than Gallup ever recorded for Franklin D. Roosevelt, Dwight D. Eisenhower, John F. Kennedy, Lyndon B. Johnson, Gerald R. Ford, Jimmy Carter, Ronald Reagan, Bill Clinton or Barack Obama. More on this in a second.

That said, this is not, by itself, some significant new low for Trump. Yes, Trump’s net approval rating (those who approve minus those who disapprove) is now minus-24, the lowest it has been since he took office. But basically for all of June so far, Trump has been in similar territory (as indicated by the dashed-line box). Trump is viewed pretty negatively — as he has been for almost two weeks.

More alarming for the president should be his weekly approval rating.

That, too, hit a new low in numbers released by Gallup on Tuesday. Over the course of the seven days from June 5 to 11, Trump’s approval rating was 37 percent. That, too, isn’t a significant difference from the week before (when it was 38 percent), but it continues a long-term downward trend.

For four of the past five weeks, Trump’s weekly approval has been lower than Obama’s ever was.

Trump’s approval numbers have been so low (and his disapproval numbers so high) in part because he entered office at a moment when partisan polarization in presidential performance assessments was higher than at any prior point. Part of the reason Trump is viewed so negatively is that Democrats strongly disapprove of him, in a way that members of the opposing party have never before opposed a new president.

But that’s not the only reason.

Most alarmingly for allies of Trump is where those declines are most significant. Since the first Gallup weekly poll, covering the tail end of January, a number of demographic groups have seen declines of at least 10 percent in their approval ratings. (Every demographic saw a drop of some measure.) Included in that number are several demographics that made up important parts of Trump’s base during the 2016 election, including those with a high school education or lower, and moderate Republicans and independents who may have reluctantly backed Trump over Hillary Clinton as the lesser of two evils.

(This week’s Gallup figure was the 20th during Trump’s tenure; the graphs above show every four weeks.)

Overall, 4 in 5 Republicans view Trump positively, which is the good news. But a drop of 10 or 11 points in approval from the groups identified above is a significant political problem for Trump and, perhaps as much, his party.

The other problem? That trend has been pretty consistently headed in one direction.