Witness these three charts from a just-released Pew Research Center study on American polarization. The main takeaways here: It just keeps getting worse, quickly. And no end is in sight.
First, here's how the two parties view each other. Note the steadily increasing "very unfavorable" ratings that Republicans have for the Democratic Party and Democrats have for the GOP. Both are on the upswing and have increased about threefold since 1994. Today, a clear and sizable majority of both parties regards the other party with disgust -- something that simply wasn't the case before the turn of the century or even when Barack Obama was elected in 2008.
Next, Pew asked people about the "major reasons" for their membership in their chosen political party. Majorities of both Republican- and Democratic-leaning voters said a major reason for their party membership was that the other party's policies were bad for the country.
In both cases, significantly fewer people cited their belief in the goodness of their own party's principles -- only about one-third in each case.
American elections are increasingly about being scared of what the other side is doing and voting against it. The two major-party nominees are viewed unfavorably by clear and growing majorities (in Trump's case, a supermajority). And the Senate can't seem to come together to make changes to gun laws that nine in 10 Americans agree with, in principle at least.
For anybody who hopes that the mud-slinging will stop and that politicians will once again return to the days of deal-cutting and compromise, you can keep waiting.
Update: The second chart above refers to people who lean towards each party, in addition to those belonging to them. This post has been updated to clarify that.