This seems more likely - how many libertarians are there in the US? Surely there are much larger groups you can appeal to if votes is what you're after
Because they are not like independents. Democrats have moved so far left that it's not even a question of who libertarians will vote for. The candidate just needs to show them a little attention so they remember to register and vote.
As a libertarian voter, the pardon for Ross was the only thing Trump did that actually brought me pause. To the point, I felt immensely guilty for not voting for him when I voted (L) because I knew[thought] I was damning Ross to a jail cell. It weighed on my conscious for a long time after the vote, an it wasn't until Trump won I felt somewhat absolved of the guilt.