i haven't seen direct data. i've seen direct polling on the absence of abortion on the ballot leading to low republican enthusiasm.
however, it fits the pattern better than cost of living issues, and i'm willing to suggest it probably did. the counter-argument is that trump really wasn't on the ballot and, in theory, and also in practice in the united states' electoral system, the election was not a referendum on donald trump.
the results in texas, south carolina and kansas have to be primarily about the candidates. texas and south carolina ran very weak candidates, relative to republican values. in kansas, the democratic candidate, who thinks everybody is going to hell, had very strong appeal to conservative voters.
further, the democratic candidate in maine was more like a republican than the republican candidate, who was essentially a democrat. sherrod brown in ohio was a very strong candidate, as well.
but as the issue that swung the election was low republican turnout, anything that fed into low enthusiasm is a defendable factor, even if i would stress focusing on local rather than national factors. when i point to abortion not being on the ballot depressing republican turnout, it has to be understood locally in a place like iowa, in contrast to a place like new york.
there was also a very bad storm in the midwest on tuesday. floods.
the governor in texas was apparently very unpopular amongst republican voters, as well.
i want to reiterate how unlikely the outcome was and how unsupported by the limited polling data that it was. a number of factors have to align very carefully to get republican turnout to cave like this. even in the absence of a vote driver, republican voters would have to see candidates in key races very poorly to have a result like this, where democrats do better in texas and kansas than they do in michigan or ohio.