Are federal elections in the US inherently likelier to be Republican than Democratic victories?

[politicallefty]

It is a rather arbitrary cutoff (and certainly too small of a data set to make serious claims). I think a better start would've been 1992. It lines up well with the end of the 40-year Democratic House Majority and the beginning of a new political paradigm. It would've added three wins to each in terms of actual wins, but a 4D-2R advantage in the popular vote.

You can't look at the House without considering gerrymandering and Republicans have had the advantage for decades now (the Republican gerrymanders after the 2010 Census being the most extreme). There's a very strong case to be made that gerrymandering cost Democrats the House this year. I think you can also make the case that that is also so for 2012 as well, though it would've been close either way. Clinton's win in 1996 is also more disappointing when you consider his failure to win back the House (and Democrats were not in a deep hole after 1994).

If you look at the popular vote of the 16 House elections over that timespan, you have half that are close (no more than 3.1%). Of the remaining half, two are more moderate wins, one for each party. When you get to the big wins, the split is 3-3, with the Democratic wins being significantly larger. (I think 2014 is debatable in that category in terms of the popular vote and it probably could be dropped down into the "moderate" category.)

Waves:
1994: R+6.8%
2006: D+8.0%
2008: D+10.6%
2010: R+6.8%
2014: R+5.7%
2018: D+8.6%

Moderate:
1992: D+5.0%
2002: R+4.8%

Closest:

1996: D+0.07%
1998: R+1.1%
2000: R+0.5%
2004: R+2.6%
2012: D+1.2%
2016: R+1.1%
2020: D+3.1%
2022: R+2.8%

Overall, in terms of the House, I think it's a wash. While Republicans did have success in holding their majority in three successively close elections after 1994, I definitely think gerrymandering is overstating Republican strength over the past decade. It would be interesting if the House really starts lining up with the presidential winner.