The dems started criminalizing policy differences during the Nixon administration, and like so many other things, the Republicans did nothing about it when they had the opportunity.
What's worse is that the GOP tends to look the other way when they SHOULD be going after genuine law breakers in the Democrat party.
There are certain elements of society that are immune from prosecution for doing their jobs (judges, etc.) even if you do happen to disagree with they way they did the job.
That immunity (with narrow, specific language) should've been passed re government officials while the Republicans were in power, knowing how the left operates.
But they didn't, and now many of them will soon find out how Scooter Libby felt.
I don't believe they'll try to prosecute GWB personally, though.
That would precipitate the type of reaction even the Dems wouldn't be able to handle.