Blago was on the Apprentice. You have to laugh about Trumpists and their idiocy about the Swamp. This was a pure shithole move. Blago was as corrupt as they come. Trump is all about corruption and doing favors for his friends.
Furthermore, Trump loves his dog and pony shows. Now, when he commutes/pardons his allies, the first words out of his ass tweeting will be how he commuted a democrat's sentence. You can count on that.
I think Trump likes to feel like a king.
Trump: "Yes, I am Trump the merciful. The peasants will see how merciful I am and love me. Just keep the peasants away and let them eat cheetos".
Trump seems to be exhibiting a pattern of pardoning and commuting people convicted of political corruption.
But he was blackmailing Ukraine, because he is concerned about corruption.
If you are a Trump cultist, this makes perfect sense. If you are a functioning, rational adult, it does not.