There is always a possible appeal to the US Supreme Court. This is the first impeachment of a Governor in the state's history, and looking at the Illinois Constitution's description, I would not at all be surprised if the Supes threw it out for violations of due process. Though it's politically motiviated, the IL constitution clearly makes it a criminal trial, and since it can deprive the man of any possible livelihood in IL for life, it should be subject to the same rules as any other criminal trial, the only differences being the jury is the State Senate, and they only need a 2/3 vote to convict.

It's going to be an interesting circus.