when thinking about any new president, and the harm or good he might do, we usually begin with his legislative agenda. the achievements that define a presidency often come early, so in the traditional model, a president rides the momentum of electoral success by quickly moving an ambitious agenda through congress. it won<u+2019>t all happen in 100 days as in franklin d. roosevelt<u+2019>s time, but typically there<u+2019>s only a short window for a president to get his proposals passed before attention shifts to the midterm campaigns. it<u+2019>s doubtful that donald j. trump has even a grade-school civics class idea of how a bill becomes a law, so it<u+2019>s long been assumed that his legislative agenda will be house speaker paul ryan<u+2019>s. the speaker will get his bills passed, with republican control of both houses of congress, and mr. trump will sign them. no doubt mr. ryan has an agenda; it<u+2019>s in the budgets he proposed starting in 2011, as chairman of the house budget committee, and most recently in a pamphlet called <u+201c> a better way ,<u+201d> copies of which he is never without. each year, a high priority for him has been a sweeping reform of medicare, establishing a system in which some older americans would get a voucher to buy health coverage on the open market. mr. ryan would also like to convert medicaid to block grants to states, repeal and replace the affordable care act, and enact major reform of both individual and corporate taxation. mr. ryan probably has enough votes for these changes <u+2014> he did get his budgets passed in the house <u+2014> but even so, the path from these rough outlines to legislation a president can sign is inevitably long and treacherous. some republicans worried about re-election will resist the medicare changes, which hit their base of older voters, and democrats should and will mobilize to make this unpopular change a 2018 election issue. other members will demand alterations in his proposals to benefit a company in their district, or a big campaign donor. if mr. ryan<u+2019>s medicaid block grants aren<u+2019>t as generous to states as the current system, some republican governors will object, backed up by their representatives. accommodating them will require spending more money, defeating mr. ryan<u+2019>s original purpose. repealing the affordable care act might seem like a one-sentence bill, but mr. trump and many members of congress have said they want to keep its popular provisions, such as the requirement to cover pre-existing conditions. insurers will balk at that requirement in the absence of either the mandate or federal subsidies, which discourage people from postponing buying health insurance until they get sick. the health care act is interconnected in ways that will make it hard to separate the popular provisions from the unpopular, and in seven years, republicans still haven<u+2019>t filled in the blank second part of <u+201c>repeal and replace.<u+201d> problems like these will appear all along the way, as any major bill winds through one or more committees in each house, is amended on each floor and finally consolidated into a single bill for the president. hundreds of lobbyists will converge on the process, pitching modifications large, small and often contradictory. there will be dozens of conflicts to resolve and choices to make. that will be true of tax as well as health legislation <u+2014> the republican house couldn<u+2019>t get a major tax reform to the floor in 2014, even after dave camp, the michigan republican who led the house ways and means committee, spent years on the details. read any of the long books written about significant legislative victories, and even with one-party control, it<u+2019>s always a high-wire act, full of moments when leaders pull the bill back from the brink of failure or force difficult votes. keeping the process on track requires a president who is fully engaged, making calls to the hill, intervening to resolve conflicts, and providing technical support through competently staffed federal agencies. it helps a lot if the president is popular and members want to be associated with him; ronald reagan<u+2019>s approval rating was almost 60 percent around the time congress enacted his sweeping tax and budget cuts in 1981. even right after the election, mr. trump<u+2019>s favorability ratings were comparable to richard m. nixon<u+2019>s in the depths of watergate, and he lost the popular vote. nor does mr. trump have warm relationships with members of congress. most have never met him, and others he has viciously attacked. mr. trump does have the roughest outlines of a legislative agenda of his own: <u+201c>rebuild our infrastructure,<u+201d> <u+201c>fix our inner cities.<u+201d> democrats welcome the idea of infrastructure spending and have said they would work with the new president to achieve it. but it<u+2019>s far from mr. ryan<u+2019>s priorities, and conservative members of the house freedom caucus will object to the increased federal spending. there<u+2019>s also no precedent for a new president to work mainly with the minority party to devise a bill. the agenda is set by the majority. yes, senate republicans may eliminate the filibuster or do as much as possible through the process of budget reconciliation, so they won<u+2019>t necessarily need 60 votes for final passage of a bill. but that<u+2019>s only one of many obstacles along the way, and with just one vote to spare, getting to 50 can be as hard as getting to 60 was during the brief period when mr. obama had the advantage of a senate majority <u+2014> he still had to convince wavering democratic senators like ben nelson of nebraska, who demanded the much-derided <u+201c>cornhusker kickback.<u+201d> to be clear, there is much to fear from the incoming administration. especially with the modern powers of the presidency, mr. trump can do staggering damage to the country and the world through judicial and other appointments, by not enforcing existing regulations, or by issuing executive orders. with mr. trump, there<u+2019>s the additional danger that he will use federal power to go after perceived enemies or mishandle any of the dozens of national security issues that will fill his daily briefing book. let those things keep you awake at night. but the idea that donald trump will become a master of the legislative process is one small thing we probably don<u+2019>t have to worry about. mark schmitt ( @mschmitt9 ) is the director of the political reform program at the research organization new america. follow the new york times opinion section on facebook and twitter (@nytopinion), and sign up for the opinion today newsletter .
trump<u+2019>s capitol hill problem
mark schmitt