Depends on the disagreement. To take this to the absurd, if I favor freedom for all and you favor slavery for some, and your side is gaining ground, that is tearing the country apart. That could lead to civil war (as it once did).

For more mundane things, we can just disagree without it tearing anything apart. For example, tariffs. Tax cuts (or increases). Funding for border patrol.

But there are some things that are existential, and conflict of those -pretty much by definition- is "tearing the country apart".

I stopped watching Maher a few years ago. Mostly because I think he is getting "full of himself" (as I heard it put recently). Plus, I already know his stances on most things (and generally agree, though not always).

As far as "my party" falling off the "leftist cliff", we aren't even close to the edge. The progressive wing may be, but they are not the entire party (nor even a majority of the party). By global standards, the Democratic Party is centrist. It is the Republicans who are falling off the right cliff-edge, straight into autocracy.