I asked this a little while back, so I'll pass along the answer: because Nascar is typically not associated with these leftist political leanings, and by association of new ideas with familiar imagery you might gently help someone become more open to considering these notions in good faith instead of a knee jerk reaction against it.

It's honestly pretty clever, and if it helps these ideas find new homes in communities they weren't always welcome in then I'd say it's worth it.