"Libby, known as "Scooter," was convicted of perjury and obstruction of justice in 2007 in connection with the leak of a CIA officer's identity."

Bush didn't pardon Libby, even though he could have. He commuted his sentence instead- to show respect for the "rule of law" and its processes, including Special Counsel authorities.

I haven't been a fan of Presidential pardons since Ford pardoned Nixon. It's an Executive power that can be used and abused for political purposes, and I think the Scooter Libby pardon is just the latest example that Trump will use the office for political expediency. Even though he campaigned against presidential overreach (when Obama was in office), or draining the DC swamp, and all that.