It is the wrong thing when they publicly consider a bunch of things they won't do, or do tiny but loud actions without consistency, that are not aligned with their political agenda but just wish to win votes.
Disclaimer: I'm not American, but that's a pattern we unfortunately see a lot these days
https://www.goodreads.com/quotes/353571-a-foolish-consistenc...
https://www.goodreads.com/quotes/738162-i-do-not-believe-tha...
“I do not believe that the solution to our problem is simply to elect the right people. The important thing is to establish a political climate of opinion which will make it politically profitable for the wrong people to do the right thing. Unless it is politically profitable for the wrong people to do the right thing, the right people will not do the right thing either, or it they try, they will shortly be out of office.” -Milton Friedman
^^^^
Similarly, the reasons the wrong people do the right things are not too important, as long as they're doing the right things.It's not a novel concept either, Biden and others regularly use this technique.
To someone with full blown TDS, sure, a Snowden pardon probably won't sway your opinion at all. But think of someone who leans libertarian and maybe doesn't love Trump but also doesn't hate him, and remembers how the Obama admin forced Snowden to flee and revoked his passport, forcing him to stay in Russia. Seeing a pardon from Trump could move them into being a mild supporter.
A lot of people have one or two big issues that their political allegiance revolves around. It can be abortion rights, gun rights, taxes, the national debt, anything. If someone's core issue is fighting the surveillance state, a Snowden pardon would be a massive change in the landscape.