Please don't misunderstand me as thinking this is a "better than them" type of thing. It actively denies opponents ammunition. I'm in full agreement that it's not enough on its own. People need to be engaged in political action as well. (Edit to add: And engaged as good, upstanding members of their own local communities.) I strongly believe one of the reasons the election was as problematic as it was all around is that there was too much name-calling and misrepresentation. It allowed people even more room to filter things to align with their own biases, which is going to happen anyway.
How many people strongly supported the candidate they ended up casting their ballot for? Both Trump and Clinton had historically low favorability ratings. If people think they're being attacked by one side or the other, it makes it all the harder for them to listen to reasoned debate, and much more likely that they'll be actively voting against a candidate.
Even this "other side" language is problematic, in my opinion. How are you going to find allies among those you don't already agree with when you think of them as "other"? How do you expect them to listen to you? People dig in, get defensive, when they feel they're being attacked. They're no longer listening. There are some people who will never listen to you, or even if they do listen to you, aren't going to end up agreeing with you. But that's not necessarily everyone you don't currently agree with. If you've already written off everyone who voted for a different candidate than you, then you're stuck with very few options. People are more complex than the effectively binary option that was the 2016 US Presidential Election admits.
It's not a "better than them" thing. It's a "what's actually going to make a difference" thing. Language alone isn't going to solve this, of course. But language used poorly can drive needless wedges between people.