The same could mostly be said of Trump's efforts to retain the presidency. I agree that the Court isn't likely to get packed, but it's because of weak leadership and lack of votes. (Basically Joe Manchin and Kirstyn Sinema aren't total partisan hacks, and that's the biggest reason it's not happening.) It's not because the party has too much character to do it. Keep in mind that the legislation isn't coming from the crackpot wing. It's coming from the party leadership.
I don't think the leadership actually thinks it will succeed in packing the court. I think the point is political intimidation - as it was under FDR. The message is "hand down left-wing opinions, or we'll pack the Court." It worked for FDR. ("The switch in time that saved nine.") I think it'll work with John Roberts. Had they not slandered and fabricated a ******** sexual assault allegation against him, it might have worked on Brett Kavanaugh.