Trump tries to prod Congress to act, not always forgiving of why things move slowly. Congressional leaders try to educate the President on the limits and culture of the legislative process.
The past few days have highlighted the disconnect between the two ends of Pennsylvania Avenue. Trump wants to tell the world that he has begun to change Washington and the country big time, that he is moving the government in dramatically new directions. His advisers are armed with talking points to prove it - steps that highlight movement on campaign promises on immigration and trade and business regulation.
To really make good on his promise to change the status quo, however, the President needs help from Congress.
He and congressional Republicans suffered an embarrassing setback when House leaders pulled the bill to replace the Affordable Care Act. Trump would like to see the House approve a bill to do that this week, although there seems little likelihood of that and his aides are trying to avoid setting up expectations that can't be met.
The message from Congress at the beginning of this big week could not be more prosaic or uninspired.
House Speaker Paul Ryan indicated over the weekend that the first - and perhaps only - priority for the House this week will be the funding bill, and that the healthcare can wait for a week or a few weeks.
These funding battles have tied up Congress in the past and in 2013 led to a partial shutdown of the government. Congressional leaders know the damage a shutdown would inflict and want nothing to get in the way of resolving remaining differences.
But the message sent is anything but what Trump would want. Instead of dramatic action, instead of acting on one of the President's big priorities, the most Congress might accomplish by the President's 100th day in office is another compromise funding agreement, or perhaps merely a short-term continuing resolution that would keep the machinery of government running while negotiations continue.
Trump is doing little to make Ryan's job easier. He wants money for his famous border wall included in the legislation to keep the Government funded. The wall is one of his signature issues, and one especially important to his base, so he is loath to get to this 100-day symbolic marker of his presidency without evidence that he has made progress on acquiring the funds to get it started.
White House Chief of Staff Reince Priebus tried to signal on NBC yesterday that funding for "border security" was the avenue for a possible face-saving way to keep the Government from being shut down. But amid whatever quieter negotiations are underway between lawmakers and White House officials, the President continues to interject himself in all the ways for which he's become famous.
He tweeted twice today about the wall. "The wall is a very important tool in stopping drugs from pouring into our country and poisoning our youth (and many others)," he wrote. "If the wall is not built, which it will be, the drug situation will NEVER be fixed the way it should be. #BuildTheWall."
Hours later, he tweeted about healthcare. "If our healthcare plan is approved, you will see real healthcare and premiums will start tumbling down. Obamacare is in a death spiral." About that same time, White House press secretary Sean Spicer was briefing reporters, noting that healthcare will come to a vote when House leaders determine that they have the votes to pass it. In other words, no promises when.
Trump also disrupted his own team when, at the weekend, he declared that he would put his tax plan into public view this week. What's coming appears likely to be little more than principles, rather than proposed legislation. Those principles might not go any further than the tax plans he proposed during the campaign.
It will be more motion without real action.
That's the difference between the presidency and Capitol Hill.
Trump likes to say things and sign things. And so, day after day, surrounded by aides or people from the outside, he makes announcements, or he puts his signature - in big strokes - on official documents, whether executive orders or presidential memorandums. These orders are not without impact, symbolically and eventually practically. He signs them and moves on. He will sign more this week ahead of the 100-day mark.
The legislative process doesn't agree with this approach to governing.
There are subcommittees and full committees, hearings and testimony, and eventually the marking up of legislation. Then there is the process of rounding up votes and holding together what has proved to be as fractured a House majority as existed before Trump arrived. House and Senate versions must be reconciled after each chamber has acted. Only then can Trump affix his signature to real legislation.
It is slow, slow, slow, as the framers intended. It was not made for the age of Twitter or 24/7 cable punditry, and certainly not for the era and impulses of President Trump.
Perhaps he will reconcile himself to the realities, but first he is trying to prod and poke and make clear his displeasure at the pace of things.
Ryan and the President remain at odds, as they've been since Trump became the Republican Party's presidential nominee last year.
They have mutual interests but competing responsibilities, and sometimes competing ideas and priorities. They are as different as they can be, a wonky House leader and a skim-the-surface president.
But this is more than a personality difference.
The disconnect between the Speaker and the President is in microcosm the gap between a president who took down the establishment in both parties last year and who understandably believes that he should be able to have wins more often than he has.
He hasn't mastered Washington, and congressional Republicans haven't mastered him.
That much is known at the beginning of this notable week.