President Trump has a habit of wantonly tying his political opponents to unpopular issues, with or without justification. He has eagerly tied problems unique to major cities to the Democrats who tend to be elected to run those cities, for example, using this strategy in his rhetoric about illegal immigration and crime.

And, more recently, when discussing homelessness. The president has put an unusual focus on the issue of homelessness, in part, he said last year, because foreign real estate investors were concerned about it. He has also used it as a cudgel in his endless war against those who would oppose him, as he did Monday.

It’s convenient for Trump to declare that homelessness is not a federal problem, a sudden reversal of the “I alone can fix it” approach to the country’s problems he debuted at the 2016 Republican convention. It’s also odd given multiple reports that he intends to deploy a federal solution for it.

That said, data from the Department of Housing and Urban Development show that homelessness is, in fact, more prevalent in states that voted for Hillary Clinton in 2016. What’s more, states that voted for Trump — and, therefore, are often led by Republicans — have seen larger drops in their homeless populations.

The HUD data are point-in-time estimates, counts of the homeless population conducted in the last 10 days of January in each year. Data for 2019 are not yet available on the HUD website. With those caveats in mind, the difference between red and blue states is nonetheless clear.

As a percentage of the overall population in the states, the drop-off in red states since 2012 is even more stark. Since 2007, blue states have seen essentially no change in their homeless populations. In red states, the population has fallen by about a third.

Trump’s discussions about homelessness seem to be predicated mostly on what HUD calls the “unsheltered” population; that is, those homeless individuals who aren’t living in shelters or other provided housing. Those populations have seen similar red- and blue-state patterns since 2007: flat for blue states, down for red states.

That obscures how important those shifts are, however. Remove the shifts in the unsheltered population from the total and the changes in red and blue states largely disappear.

Isolate that population, and the extent to which the unsheltered population is largely a blue-state problem becomes apparent.

This is in part because the state with the largest homeless population is California, where it’s much easier to be unsheltered than it is in, say, New York City. New York City is the area (referred to as a “continuum of care” by HUD) with the largest homeless population, but Los Angeles, San Jose and San Diego had the largest shares of the unsheltered population in January 2018.

Much of the reason that the blue-state homeless population hasn’t fallen since 2007 is growth in New York state itself. By contrast, the population in Florida, the state with the third-largest population, has fallen since 2012.

Trump would quickly point out that the governor of Florida from 2012 to 2018 was now-Sen. Rick Scott (R-Fla.), a strong ally of Trump’s, and that the governor of New York since 2011 was Gov. Andrew M. Cuomo (D-N.Y.).

The HUD data breaks out its “continuums of care” (CoCs) by type. Since 2007, the homeless population in every type of CoC has fallen generally after a post-recession surge. But suburban, small city and rural CoCs all saw homeless population declines of at least a fifth, while the major-city population fell by only about 3 percent. Here, too, there’s a big divide between red and blue states: In blue-state major cities, the homeless population rose since 2011 while, in red states, major city homeless numbers dropped steadily.

Half of America’s homeless live in major cities, four-fifths of them in blue states. The data above suggest that Trump’s tweets aren’t simply the president picking on cities as centers of homelessness and incidentally dinging Democrats. Instead, there indeed are real differences in how the homeless population has changed in red and blue states.