I honestly don't care about Spirit's ideological leanings - they're a crappy airline with incredibly poor service - so I don't need to boycott them - I already wouldn't use them.
I once was flying to the Bahamas on Spirit, and I showed up at the terminal to find a line spilling outside the building and out onto the sidewalk. I had to wait more than an hour to talk to a ticket agent (most of that time in the 95 degree sun), and ended up missing my flight (and taking a later one).
Why so long? Too few agents, and the genius of an airline had scheduled five flights that morning to all leave at almost exactly the same time. Any airline with an ounce of sense staggers their departures for exactly that reason. But no, "catch the Spirit".
I won't ever fly them again: I guess I've already started my own personal boycott, because they suck. I won't even get into their ridiculous baggage charges and the lack of amenities, including food, while in-flight.
Fox News does support the Tea Party. And by support, I mean promoting them on-air, not just covering them. http://mediamatters.org/reports/200904080025