Unknown for sure. People have been trying to get Trump for years... WAY before he became a political figure. For example, he's pretty famous for hiring contractors to do work for him, then refusing to pay and saying the work was bad. Then he basically lawyers them to death by delaying any proceedings until the folks in question have to give up.
But politically motivated? I think so. That's a standard roadmap to a political future... a prosecutor that goes after the people that other folks couldn't get. It happens ALL THE TIME. If he convicts Trump for this, I wouldn't be surprised to see him in congress or the governor's office in a couple of years. So yeah, I think its political for sure. After all, the guy got elected for bragging that he was going after Trump. I'm guessing that he'll call it a promise kept.
The good thing is that prosecutors don't get to just find people guilty... political things aside. They have to bring charges before a grand jury (which to be fair, is NOT a hard thing to do). THEN he has to prove to a jury that these charges are real beyond a shadow of a doubt. And that is VERY hard to do.
I don't find it particularly disturbing b/c I don't really pay much attention to it. Trump is charged with a crime... So what? He had to show up at court and then leave again. No bail to make, no cuffs, didn't have to agree to restrict travel. He has to go to trial and THEN we find out if this is a big deal or not. Until then, I don't think ONE person has changed their minds on Trump.