# What do the numbers mean after the R and D when describing seats in the House of Representatives?

I'm sure this is basic but my Google search results are overwhelmed by links to current events.

[...] Republican Rep. Lauren Boebert appears in real danger of losing her R+15 seat [...]

What does R+15 mean? Is it related to the numbers on the rightmost column of this table?

I'm sure it's not related to the leftmost column, e.g. AZ-2, which I think identifies congressional districts.

The column is labeled "Current lead." A lead of R+15 means the Republican candidate is leading by 15 percentage points. In the sentence you quote, it is instead being used to refer to the "partisan lean" of the seat - that is, how much further to the left or right it tends to vote relative to the national popular vote. R+15 in that context means "this district normally votes for the Republican candidate by 15 points, plus or minus whatever the national popular vote margin was."

It should be noted that this is a slight simplification, because:

• Election results are generally not 100% perfectly correlated between different districts, or between the district level and the national level.
• Election results are subject to variations in elasticity - that is, some districts are more responsive to swings in the national popular vote than others.
• Partisan lean has to be approximated based on polling and election results, and this is an inherently noisy and imperfect process.

So on the whole, an "R+15 seat" should simply be understood as "a very Republican-leaning seat." The number 15 is not precise enough to carry a more specific meaning than that.

(The numbers in the leftmost column are indeed congressional districts.)

• I believe that in the sentence OP quotes, the "R+15 seat" refers to this: en.wikipedia.org/wiki/Cook_Partisan_Voting_Index Nov 9, 2022 at 21:38
• @wonderbear: That's just one way of calculating partisan lean. It does not materially differ from what I describe in my answer, other than the fact that it is calculated by a specific organization using a specific method. Nov 9, 2022 at 21:42
• Typically you'll find polls looking at these numbers closer to the next election as a lean strong polling in districts that don't lead towards candidates from that party is a bellweather for where the political favor of the general public is leaning. Typically these numbers will be reflective of house seat for that district or the presidential vote as they are more frequently voted for smaller, more regional population of a state. Nov 9, 2022 at 21:52
• @hszmv: I didn't understand the first sentence of your comment at all, and the second sentence is difficult to parse. Nov 9, 2022 at 22:03
• see denverpost.com/2022/11/09/… (paywall) which supports this explanation in general: Colorado, and the rest of the nation, watched in amazement Tuesday night as Rep. Lauren Boebert’s anticipated 15-point victory slipped to where it stands now, with her Democratic opponent, Adam Frisch, up by about 62 votes. Nov 10, 2022 at 0:02