Are Republican voters more likely to vote a split ticket than Democratic voters?

Question

In a 2016 exit poll I saw that 13 percent of house GOP voters said they voted for Hillary Clinton. Only 10 percent of house Democratic voters said they did the opposite.

Was this also true under Obama? Don’t go back any further than 2008 or maybe 2004 because that is when/after most voters slowly stopped splitting tickets. In other words: are Republican voters more likely to vote Democrat than Democratic voters are to vote Republican?

Here is the CNN poll: https://edition.cnn.com/election/2016/results/exit-polls

Answer 1

The difference between Democrats and Republicans is unlikely to be statistically significant.

According to the 2016 exit poll you cite, 90% of House Democrat voters voted for Clinton, while 87% of House GOP voters voted for Trump.

In the 2012 exit poll, the same figures were 93% for the Democrats and 92% for the Republicans.

Of course, these are both national figures, and we would be better able to give a more definitive answer if there were a breakdown by state. If we saw a consistent breakdown across most of the 50 states, then I'd be better prepared to argue its case. As it stands, the difference could just be down to sampling.