No doubt President-elect Donald Trump will face his share of unexpected procedural hiccups as he begins his four-year term on Jan. 20.

Doubtless, too, that his focus at the start of his term will not be the focus at the end of it. Events tend to change what a president can do.

Last Wednesday, Trump offered a smorgasbord of proposals, some of them specific, some of them vague. Given his campaign rhetoric, these will be easy for opponents to caricature: Mass deportations! Millions losing health care immediately! Trade wars!

The reality is that the pace of change, even at the speed of Trump, will slow considerably as it strains through the grind of Washington. The press will not let up in its newly found, if somewhat tarnished, role as truth-teller. The gaps and inconsistencies in his policy proposals, which were back-seated to coverage of his personality and professional history, will become more salient. And Trump might pretend to ignore the equally-as-tarnished opinion polls, but if he is human, he will pay close attention to them.

He has several gating ideas: He'll protect workers, clean up Washington, and restore law and order.

Trump will want a major victory early. A successful Supreme Court nominee, from a list he has already provided, might give him breathing room with conservatives who mistrust him, as will the inevitable fevered, ultimately futile opposition from Democrats. Their opposition to his political appointees will be as implacable as Republican opposition was to President Obama's, and Democrats will be under intense pressure from their base to try and disrupt any traction that Trump might generate from early and easy confirmations.

The new president will need more to generate real momentum: a big domestic policy accomplishment. In the abstract, he can count on the support of his entire party. On a concrete level, he might find that Republicans cut from a different part of the cloth will offer him surprising resistance. His mandate might not be theirs. He might decide on something that commands majority support from a cross-section of Americans. He is fickle that way.

Repealing and replacing ObamaCare will take a while. Some provisions of the bill haven't kicked in yet, and the Affordable Care Act's reach extends to dozens of government agencies, and into state governments. It has metastasized; it cannot be extricated from the body politic like a benign tumor. A number of Republicans want ObamaCare to slowly starve itself to death, exhausting the available supply of governments funds over the course of several years. Its protections remain widely popular and the prospect of many of Trump's own voters going without health insurance will slow down the pace of reform, perhaps considerably. By the end of next year, the American health care system will look a lot different than it does now. How Trump gets rid of ObamaCare while keeping his promise to cover everyone is a mystery at the moment.

In theory, it will be easy, with command of Congress and the White House, to pass a budget. Republicans will roll over and deal with the deficits that Trump's proposals will create because the GOPers overwhelmingly favor the huge tax cuts that will accompany them. But what if that budget contains significant new spending for infrastructure projects? Many House Republicans will face significant pressure to fight against government spending tooth and nail. Senate Republicans will chafe against Medicaid cuts, which would hurt the poor.

On immigration, Senate Republicans already support spending money to build a border wall; they've been appropriating it for years under President Obama. But the predicate to that, which Trump has established in hints, is a more comprehensive immigration plan that could generate support from Democrats in offering a pathway to citizenship for undocumented immigrants. It is not clear that the votes are there. Similarly, although he can ask Congress to cut funding for "Sanctuary Cities" — which protect undocumented immigrants by policy — it would pass only as a standalone bill. When merged with Trump's more controversial proposals, it becomes a bargaining chip.

Trump wants to establish term limits on members of Congress. That's a non-starter, even if Congress reads the election tea leaves the way that Trump does. Other proposals to "drain the swamp" — including bans on foreign lobbying and measures to curtail special interest influence over politicians — could sail through.

Some of his plans might draw support from unusual allies. Bernie Sanders pledged to renegotiate bad trade deals and to officially label China a currency manipulator. Many Democrats, and some Republicans, support both of those actions. But most conservatives remain enthusiastic free traders.

So much depends on how Trump gets along with Paul Ryan, assuming the Wisconsin Republican remains speaker of the House. They share some concerns — the size of government and infrastructure investment are two — but their minds diverge elsewhere. Ryan and Trump have profoundly different approaches to criminal justice reform, for example.

And both will be held accountable to vastly different publics. Their interests might overlap simply in the vein of both wanting to do something, and in the need that both have to show that they can work together. Will Ryan, who represents the swamp that Trump wants drained, feel empowered if he retains his speakership? How much of a mandate will Trump claim?

Republicans may well come to understand that Trump won because Hilary Clinton lost (indeed, she was, in the end, a more popular candidate). As much as they need Trump's voters — and the anger of those voters — to sustain their political careers, they will be aware of its limits.