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

[Torie]

The margins are narrow enough, and the sample small enough, and each election cycle dissimilar enough, that I don't think there is much statistical significance to be had out there.

That said, rate candidate quality for each POTUS nominee, and where one party has an edge over the other, assign a headwind or tailwind to that, and maybe aside from the small sample size, that might bring some order to the randomness. It was probably pretty even in 2000 and 2004, with the candidates being mediocre (Dubya, Gore and Kerry), then Obama had a fairly sizable edge over the gunslinger impulsive McCain and the then Ken Doll like patrician Mittens, and then there were two about equally bad candidates in 2016, and in 2020 also two subpar candidates, but by this point, Trump had moved on to near horrifically bad, while Biden was more of just the benign null set.

I yearn for the good old days of GHWB and Bill Clinton. Where have all the flowers gone?