# About how many Joe Biden voters are represented by Republicans in the House, and vice versa?

I want to know about how many people are living in places where they are represented by people of the other party. I know there were a lot of crossover districts, but that is not the point. In other words I want to know how representative the House of Representatives is based on presidential results.

There are resources breaking down the votes by congressional district for president.

Per this metric, Pennsylvania's 3rd district, where 9/10 voters voted for Joe Biden, is the most representative. On the other hand, the least representative is New York's 24th district, where a Republican is representing it despite Trump getting only about 45% of the two-party vote.

• By "representative", I mean each district reflecting its voters. May 20, 2021 at 10:31
• One problem, even if this is answerable, is that there are some who consider themselves Republican, but were unable or unwilling to vote for Trump. They live in districts which are Republican represented, but are Biden voters. And unless I mis-understand your question, that isn't what you want. May 20, 2021 at 10:34
• Do you view representativeness relative to the size of the district (inhabitants / actual voters)? Would a map that's dark blue (overwhelmingly Democrat) to light blue (tossup that went to Democrats) and similar for red and Republicans (on the same map) answer your question? Basically, the lighter the districts the less representative they are per your description. Perhaps something like the partisan voting index is what you're looking for?
– JJJ
May 20, 2021 at 10:35
• In other words, I am talking about how many voters live in districts where they are represented by a party other than the party's candidate they voted for for president. In Wyoming for example that figure is 73,491 or 100% of Biden voters in the state. Hope that is a good description. Yes JJJ I do view representativeness relative to the size of the district in terms of how many voters there are in it. May 20, 2021 at 10:40
• Good question, but when interpreting the results, note that the most popular party in the US for many years (not sure about 2020 however) has been "none of the above" ie "independent". That's just over a third of voters, and in some places they have a habit of "splitting the ballot" between parties May 20, 2021 at 12:50

We can calculate this using the Daily Kos 'Pres-by-CD' dataset. This answer is based in part on code used in my answer to this related question about the number of split districts in 2020, which also uses the NYT feed to determine the winners of each congressional district.

Unfortunately, their main dataset found here only reports percentage totals rather than raw population totals. I had to scrape the more detailed state breakdowns for these figures - the resultant totals can now be found in a more convenient form on GitHub here.

In terms of raw numbers, 30,668,880 Biden voters (about 37.7% of all Biden voters) live in congressional districts represented by a Republican in the House of Representatives, while 27,049,563 Trump voters (36.4%) are represented by a Democrat.

The district with the most Biden voters represented by a Republican is Montana's at-large congressional district, with 244,786 votes for Biden. The district with the most Trump voters represented by a Democrat in the house is Iowa's 3rd congressional district, with 224,726 votes for Trump.

It's worth bearing in mind, of course, that just because a voter supported one presidential candidate or another, it doesn't necessarily mean that they supported a congressional candidate of the same party.

• “doesn't necessarily mean that they supported a congressional candidate of the same party”—right, which is why, to my mind, this question would have been more interesting if it had asked how many people were represented by a Representative they did not vote for. (+1 regardless, mind—this is a great answer to the question asked.) May 20, 2021 at 20:56
• Another +1 for the last paragraph. I personally voted for a Republican member of Congress, but not for Trump. Also, Joe Biden and Donald Trump, contrary to popular belief, were not, in fact, the only options to vote for President. Granted, they were the only ones with a reasonable chance at winning, but they weren't the only options. Almost 3 million Americans voted for someone who was neither Joe Biden nor Donald Trump for President in 2020. Nearly 8 million voted for someone other than Clinton or Trump in 2016. May 20, 2021 at 22:29
• @KRYan is a very similar calculation with a similar answer easily adapted from the given code: You have to just add up all the votes for each losing candidate. In a perfectly-mixed country that would be that votes 50-50 for two parties that would be 50% (as it would be a cointoss who gets it), perfectly mixed voting 49-51 it would be 49% as 100% of the "51" party would be elected (and same for other ratios). However districts are usually lopsided (rural Nevada heavily Trump, Las Vegas Biden); my guess is they're similarly lopsided for Presidential as Senatorial elections. May 21, 2021 at 15:10