To be honest if Trump would've pardoned him in his first term it would've been way too short of a sentence for what he did. Though I hate the usual libertarian defense that makes him out to be an innocent martyr, I think that 10 years is somewhat enough for what he did. It would have been a normal sentence in a lot of countries outside the US.

Thanks. I appreciate your view on the sentence, but I'm interested in why Trump would issue a pardon.

I'm unconvinced that Trump in 2020 thought Ulbricht's total sentence was okay, but four years later has apparently changed his mind. So who's the client here? It doesn't seem to be Ulbricht - is it libertarians in general? Why does Trump, as a second term president, actually care?

There are credibility issues if you make promises you don't follow up on, especially very public promises that are completely within your power to carry out; there are no limits on the presidential pardon power, barring that it only applies to federal crimes.