The American National Election Studies contain data on various aspects of political attitudes and involvement over time (for some questions the have survey data back to 1948). [NOTE: several commenters have correctly pointed out something I didn't think to mention, which is that the ANES does that annoying thing where different graphs have different starting points on the y axis, and none of them start at 0, so you have to check the y axis carefully to see what percentage point you're at. I know that's super annoying, and I agree with commenter OP Minded that "There should be a law that requires all graph makers to use zeros at the xy axis." Anyway, take care when looking at them, and if you use them in a class, be sure to point this out to students, and maybe even use them as a good example of how graphs can be easy to misinterpret depending on the scale used.]
Here is a graph who responded “don’t know” or “don’t care” to a question about whether they care about who wins the presidential election:
Here is a graph of those who responded they “care a good deal” about who wins:
So for whatever reason, we see that over time a greater proportion of the electorate claims to care who becomes president. This may reflect an increased sense that who the president is really affects policies that the person cares about, or possibly that it’s become less acceptable to say you don’t care about politics or who the president is (or some other factor; I’m not up on the literature on this topic).
The next two graphs show responses to a question that asked how well the phrase “moral” describes presidential candidates from each party. First for Democratic candidates:
So…even before the whole sex scandal and impeachment trial, Americans didn’t seem to think that “moral” was the most appropriate term for Bill Clinton.
And now for Republicans:
It looks like, if you take out the Clinton years, respondents perceive Republican candidates as somewhat more moral than Democratic ones, but not by a huge margin. Aparently they thought both George H.W. Bush and Bob Dole were way more moral than Clinton…they just didn’t so much, you know, vote for them.