For all of the appeal his message might have much of what he is promising to do — on his own, and through congressional legislation — couldn’t be accomplished in the first 1,000 days of a Trump administration, much less the first 100. If Washington’s ability to gridlock even the most ambitious of presidential agendas were to block Mr. Trump’s White House plans, he would still have the bully pulpit, of course." Take trade: The problem for Mr. Trump — or any president who wants to get tough on trade violators — is that, in the global economy, imposing tariffs on competitors abroad could have serious economic consequences at home by sharply raising prices on imported goods."..."But for all the uncertainty around what might happen after Jan. 20, 2017, Mr. Trump’s much-talked-about unpredictability is proving to be a boon for Washington’s legions of lobbyists.