Being an American of Italian descent I already know that.
Surely you're not going to dispute that the majority of people in the world (and ESPECIALLY in the USA - who are not immigrants) who spell "favor" as "favour" and "labor" as "labour" are liberals.
Now, there are exceptions. There are a few that are more conservative such as: The Daily Mail (UK), Canada Free Press...etc and maybe the above website. I stopped at "favour" for the reason you suspect but also because I have not concluded that Obama has not yet stolen this election.
And let it be known, I was never a Romney supporter. I do think he may have been cheated though. That became the primary reason why I did not continue after I stopped at "favoured".
There have been many news reports of fraud during Tuesday’s elections. I am certain that Hussein stole it. Favor = favour; color = colour; rumor = rumour — I too observe spelling differences. Great profiling tool, hmm? With many exceptions, of course.