The graph suggests that a smaller number of people are saying that Santa is an independent or something else (usually people just say they don’t know or aren’t sure), and a larger number of people saying that Santa is either a Democrat or Republican.
The main caveat, however, is that in 2012, the survey question did not explicitly give “independent” as an option, listing only Democrat, Republican or “something else.” So it is possible that the 2012 poll may exaggerate any politicization. And, of course, there is the usual caveat of trying to extract a meaningful trend across only three polls.
Nevertheless, the potential for a trend is intriguing and in line with other research that shows a growing salience of partisanship, even in non-political contexts.
Meanwhile, across the pond, Jennings reports on a 2013 poll in England about the partisan preference of Father Christmas, who appears to lean left: