E.J. Dionne in the WaPo sums it up nicely.
The key to corruption is operating in the dark. This bill is a mess of opaque provisions that almost no one outside the ranks of tax lobbyists understands — because many of these giveaways were written or inspired by lobbyists themselves.Needlessly rushing a massive special-interest tax bill through Congress is the antithesis of good government. This doesn’t seem to matter anymore, even to Republicans who built reputations as champions of moderation, openness and rectitude.
Source: Republicans are joining a festival of corruption – The Washington Post