Across these three states, we see that if anything, the relative gap between Democrats and Republicans has gone in the direction of Republicans (North Carolina and Pennsylvania) since the election. This fits with what occurred in 2016 as well. Democrats tended to lose ground in registration immediately following the election.
Certainly, there is no data in here to suggest a mass exodus from the Republican Party.
Of course, changing registration is onerous. People can be changing their party allegiances without changing their registration. Additionally, many states don’t have registration by party…
We’re basically in the same political environment we were heading into the 2020 election, which was quite competitive. President Joe Biden defeated Trump by under 5 points in the popular vote and the race was even closer in the Electoral College. The state that put Biden over the top in the Electoral College, Wisconsin, was decided by a mere 0.6 points.