Won’t really harm him at all, if Republican voters were prepared to vote for Roy Moore who had molested an underage girl they won’t blink at this.
All this will do is feed into the bullshit Trump speaks about being targeted by the courts, in this case this is untrue as it was a civil trial. In the case of weak sauce New York case of misusing campaign finance (which to some degree every presidential candidate has done) it looks like a witch hunt.
I get that people don’t want him to run for president especially with the headache he created last time, but they are going to have to accept that the Republicans had the opportunity to convict him in the senate and bar him from political office but they elected not to. So going to have to accept that you can only beat the guy at the ballot box.