In his own politics, Jonathan Swift was a Tory. But I do not think that this ideology comes through in the book. In the book, Swift seems to be commenting mainly on the flaws of the political system as a whole. He is criticizing both parties in England, not just the Whigs.
You can see this most clearly in the part of the book where Gulliver is in Lilliput. In that part, Swift satirizes the British political system, saying that it is petty and corrupt. He says that people go through all sorts of things to gain office but none of what they go through is at all related to actually governing well.
Swift also argues in that part of the book that there is essentially no difference between the two politcal parties.