Can a President Trump work effectively with Congress? That may seem like an unnecessary question, since his fellow Republicans hold majorities in both houses. But historically, a new White House can run into trouble with Capitol Hill, regardless of its partisan makeup.

Before the election, we interviewed Office of Legislative Affairs (OLA) directors from the past four presidential administrations to explore what matters in executive-legislative relations. Here’s what they told us.

1. Watch the calendar.

This might be most important. President Obama’s first OLA director, Phil Schiliro, warned that a new administration must be mindful of the calendar.

New administrations are often surprised by how many legislative agenda items they must confront in the first year, beyond those they’ve chosen. The Trump administration is set up for a full docket. An emerging strategy for quick movement on repealing the Affordable Care Act (ACA), also known as Obamacare, would first require action on the unfinished fiscal 2017 budget resolution.

House leadership plans to adopt a short-term spending bill in December that would fund the government until March or April, at which point further action would need be required to avoid a shutdown. There are the fiscal 2018 budget resolution and appropriations bills. Possible conflicts loom over the debt limit and sequestration caps. There will also be confirmation hearings and votes on Trump’s appointments — from his Cabinet to the Supreme Court.

Taken together, the congressional calendar for 2017 begins to look like, as House Minority Leader Nancy Pelosi recently put it, “a kettle of fish … they can’t even imagine.”

2. Building relationships can be very hard.

Schiliro described the Obama administration’s 2009 engagement as “constant”:

He [President Obama] did constant outreach to Congress: one-on-one meetings … the perception is so different from the reality. The first four months, we had cocktail parties every Tuesday or Wednesday at the White House until every senator and House member who was willing to come had participated. The president and the first lady usually met 30 folks at a time, the president also had private lunches, small-group meetings, and phone calls.

Yet the Obama team soon saw the visits as too often fruitless. “That was a common complaint, especially the first year and a half, was that the president — it’s too much of his time,” Schiliro said.

Pat Griffin, who served as OLA director under President Bill Clinton from 1994-96, believes that members of Congress also feel visits can be a waste of time. “The interaction was one that the members, after a few glasses of wine and some shrimp, really resented, because … they felt like they were brought in for some lecture.”

In both administrations, as time went on, the official visits grew fewer and the president more withdrawn.

Political science research confirms that interpersonal contact only helps so much. Political scientist Matthew Beckmann, for example, shows that interactions between the president and congressional leaders of the opposite party — key when presidents need votes from their partisan opponents for certain legislation — are often shaped not only by personal relationships but also by the political strength of the president and the institutional strength of congressional leaders.

3. Keep campaign staff out of legislative affairs. Bring in people with congressional experience.

Holdovers from the Trump campaign can get in the way of effective relationships with Congress, our interviewees say.

“The campaign has an inordinate impact … in the first year,” Griffin said. “When I got there, it was clear, the campaign folks from the ’92 election still had their fingers in how we were going to deal with the Congress.” He explains that the attitude was: “We don’t need them [Congress], we didn’t need them to win, you don’t need them to be the guy you can be.”

Trump’s campaign operation emphasized political outsiders. A group with that identity may be naturally suspicious of anyone considered an insider. This is combined that with the fact that a number of congressional Republicans were cautious or unhappy about Trump’s candidacy. With the wrong emissaries, there’s plenty of potential for conflict.

But the best qualification for a legislative affairs director is pretty straightforward: experience with Congress.

“A president is well served by having somebody who has spent time on Capitol Hill,” said Fred McClure, President George H.W. Bush’s first OLA director, matter-of-factly. Any executive branch experience is a bonus.

In addition, an administration might wish to find staff with expertise in issues that may become legislative battlegrounds. For instance, Schiliro presumed that financial reform would be part of Obama’s first-year agenda following the Great Recession. Partially for this reason, he appointed a former staff director of the Senate Banking Committee, Shawn Maher, as a deputy. Since health care, tax cuts and infrastructure will probably be on the agenda for 2017, the Trump administration may find individuals experienced with those areas on the Hill useful.

4. Keep legislative staff involved as you make policy decisions 

George W. Bush administration OLA Director Dan Meyer spoke about how important it is to have policy informed by knowledge of congressional reality. “You’re so often in these meetings and you have somebody who’s never been on the Hill, ever, who is saying, ‘Well, let’s just do X,’ and you’re sitting there thinking, ‘That’s going to get three votes out of 435 in the House of Representatives.’ ”

Without OLA involved in policy planning, an administration’s congressional relations may be muddled or inconsistent.

Meyer notes, “[Karl] Rove drove some of [Meyer’s] predecessors crazy … because he basically was his own one-man Leg Affairs shop, and he wouldn’t keep [them] informed, which is very disruptive.”

Senior officials in the mold of Rove do have a major role to play in advancing an agenda. If they have relationships with Congress, they can be deployed effectively. But if it’s not part of unified, strategic effort and message, things can go awry.

So far, the Trump transition has used Vice President-elect Mike Pence to head congressional outreach, which could challenge the next OLA director’s authority and lines of communication. Or it might go smoothly. There can be numerous cooks in the kitchen, so long as Pence, incoming Chief of Staff Reince Priebus and anyone else the administration sends to the Hill are working as a unit.

Why does all this matter?

Polarization is high. President-elect Trump is divisive. However, the new president does come to office with majorities in both chambers of Congress. As it charts its legislative strategy, the incoming White House might wish to learn from its predecessors’ experience.

Tony Lucadamo is lead policy analyst at the University of Virginia’s Miller Center. Follow him on Twitter @tonylucadamo. 

Molly E. Reynolds is a fellow in governance studies at the Brookings Institution. Follow her on Twitter @mollyereynolds.