Disconnect the statement from actual politics and think about the concept in a more local setting. Here's a somewhat contrived example.
There are two engineers in your company trying to work out the best way to reduce the rate of bugs being introduced into a system. One of them is advocating for pair programming, and the other is advocating for a dedicated testing team. Both are trying to convince the other engineers that their method is best.
They may argue in good faith. They may resort to calling the other silly names. This is politics on a local scale. There's nothing to imply that the other side is evil, immoral, or even wrong. The fact that current democratic politics has devolved into mudslinging isn't an inherent fact of politics - it just seems to be an effective way to win these days.
There can absolutely be moral disagreements but it's not a given. That's probably the main point contested in this thread - that not all politics is about thinking the worst of your opposition. Certainly it happens, but it's not predicated on it.
There are two engineers in your company trying to work out the best way to reduce the rate of bugs being introduced into a system. One of them is advocating for pair programming, and the other is advocating for a dedicated testing team. Both are trying to convince the other engineers that their method is best.
They may argue in good faith. They may resort to calling the other silly names. This is politics on a local scale. There's nothing to imply that the other side is evil, immoral, or even wrong. The fact that current democratic politics has devolved into mudslinging isn't an inherent fact of politics - it just seems to be an effective way to win these days.