President Donald Trump gives the impression of having done everything in his first month in the White House — except think about Congress.

A couple of months ago, there were congressional Republicans reluctantly on the Trump train who would have welcomed such neglect. They believed that Trump might be a figurehead president. He would tweet, give speeches and wear red hats, while they set the agenda. He would “sign our stuff,” as some Republicans put it, but otherwise leave them alone.

An article in Slate in November expressed this expectation under the headline, “Welcome to the Paul Ryan Presidency.”

The view of Trump as little more than a presidential autopen has turned out to be wholly mistaken. First, it underestimated Trump’s ability to establish air, sea and land dominance in the nation’s political conversation to the exclusion of other Republican voices. Two, it failed to appreciate how necessary presidential leadership is to getting anything done on Capitol Hill.

At this rate, congressional Republicans won’t send the president anything significant to sign, let alone set the agenda.

Trump has totally eclipsed congressional Republicans by creating a sense of headlong action through the sheer force of his frenetic personality. Watching cable news, you could be forgiven for occasionally forgetting that there is a coequal branch of government called Congress, except insofar as its members are forced to react to whatever Trump is saying or doing.

Some of this motion is significant. Trump nominated Judge Neil Gorsuch, who will get confirmed to the Supreme Court. Trump’s commitment to begin enforcing the immigration laws again is a signature departure from the status quo. But many of the Trump-initiated battles of the first month — over crowd sizes, illegal votes, fake news and the rest of it — have fed the perpetual outrage machine with pleasingly empty calories.

Normally, a new president spends his early days proposing legislation and shepherding it through Congress, then — assuming success — regaling in signing ceremonies.

This is not part of the job that Trump has yet embraced, or shown much awareness of. But it is not proving a boon to his party’s legislators.

Congress is naturally fractious and insular, and left to its own devices will often spin its wheels or make shortsighted decisions. The foray out of the box by House Republicans this year was going to be the elimination of Congress’ own independent ethics office. The next step after that was going to be to repeal Obamacare without a replacement. Neither was a good idea, and each reflected greater concern for internal congressional dynamics than political reality. Trump, correctly, dissented from both moves.

That Congress listened suggests the enormous sway Trump has. His hold on the GOP base is formidable. Couple that with his prodigious media megaphone, and Trump could break isolated senators or members of Congress resisting his congressional agenda like a twig.

If, that is, he has such an agenda. No one knows what his infrastructure plan is. Or what he wants on Obamacare replacement, which will badly divide Republicans. Or where he comes down on the contentious issue threatening the ultimate passage of tax reform, the border adjustment tax.

These aren’t details, but core questions that must be resolved if Trump is going to have a successful first year legislatively. Trump could address all of this in his speech to the joint session of Congress next week. And the wheels are turning on Capitol Hill. But every day that passes means Republicans have lost a little momentum.

If Trump turns out simply not to have any interest in legislation, it likely won’t augur a period of strong congressional governance, but of drift and perhaps outright failure.

Capitol Hill is dependent on Trump, not just to sign bills, but to lead. Republicans don’t need him merely to be president; they need him to be a good president, which means that in his busy days he must find a little time for Congress.