Rep. Will Hurd (R-Tex.) will not seek reelection to the House next year. He becomes the eighth House Republican in this Congress to decide to move on without seeking higher office.

But Hurd’s retirement is more significant than possibly being at the front end of a trend. His district, Texas’s 23rd, is the only one the border with Mexico that’s still controlled by the Republican Party. That might change: In the 2016 election, Hillary Clinton won the district by a narrow margin.

Hurd is also the only black Republican in the House. He is one of two black Republicans serving in the Senate, House or as governor, joining only Sen. Tim Scott (R-S.C.) in that group. Of the 276 Republicans serving in any of those three capacities, 14 are not white including Hurd. Of the 303 Democrats serving in the Senate, the House or as governors, 104 are nonwhite.

Of all of those Republicans, 24 are women. Of the Democrats, 112 are. In fact, 239 of the 276 Republicans are white men, about 87 percent of the total. Forty-four percent of the Democrats are white men.

That the GOP is so homogeneous on race shouldn’t be terribly surprising. Pew Research Center data released last year indicates that about 83 percent of Republicans are white, compared with 59 percent of Democrats. The density of whites in the GOP is heavier now than the density of whites was in the Democratic Party in 1997.

There’s a little-recognized problem that emerges here, one that we touched on last month in assessing the Trump administration’s focus on adding a citizenship question to the Census. With race tracking closely to party in certain contexts, race becomes a proxy for partisanship — in a very polarized moment.

Republicans, for example, often advocate policies that are ostensibly aimed at tamping down voter fraud but, given the near-total absence of evidence of such fraud, serve mostly as mechanisms for making it harder for poorer — and therefore more heavily nonwhite — voters to cast a ballot. It’s tricky to figure out a way to make it harder for Democrats to vote. It’s much easier to come up with ways to make it harder for black people to vote, which largely has the same effect.

The Supreme Court gutted the Voting Rights Act in 2013, removing restrictions on states that had historically targeted black voters to inhibit their ability to vote. Analysis by the Brennan Center released last year shows that places where the VRA had once protected voting rights saw higher rates of purging voters from voting rolls than places where the VRA hadn’t been in effect.

It’s easy to see how this could be self-fulfilling. A Democratic Party with more members who are black or Hispanic is a party more likely to put forward nonwhite candidates who will, if elected, presumably more effectively represent the concerns of their communities. A Republican Party that’s more heavily white may be less able or interested in doing the same.

We can’t consider this question without mentioning President Trump’s recent attacks on Democratic elected officials. Over the past two weeks, he has isolated five Democratic members of the House, all of whom are not white. He’s attacked them in often racist terms, telling four Democratic women to “go back” where they came from (generally the United States) and attacking the district of Rep. Elijah E. Cummings (D-Md.) as a “disgusting, rat and rodent infested mess.” Trump’s reelection strategy for 2020 appears to be to explicitly highlight the racial differences between the party, framing his opponents as sympathetic to nonwhite immigrants and unwilling to defend traditional America, which is often a not-too-subtle way of saying white America.

BuzzFeed’s Miriam Elder was at the president’s campaign rally in Cincinnati on Thursday and spoke with some Trump supporters.

There are a lot of reasons to want to leave the House, including the reasons articulated in this very good overview of the state of federal public service. It’s also easy to read more into one retirement than is warranted, though Hurd is also one of the few Republicans who has publicly spoken out against Trump’s rhetoric on race.

That Hurd has decided to leave, though, points a spotlight on what his party’s representatives will look like once he’s gone.