President Barack Obama shook hands with lawmakers as he strode down the middle aisle of the House of Representatives before his final State of the Union, breaking into a wide smile when he saw a very familiar face.

“Eliot, you’re here,” Obama said.

“Would I be anyplace else?” Rep. Eliot Engel, D-N.Y., replied.

For nearly three decades, Engel has been on the aisle for every presidential address to Congress. For a fleeting moment, it’s just him and the president – two Republicans and two Democrats since he began the tradition in 1989 – shaking hands in a show of support for the leader of the free world.

Engel could be someplace else Tuesday night, when President Donald Trump strides down the House’s center aisle to deliver his first address to a joint session of Congress. It’s not technically called a State of the Union this early in a presidential term, but Trump’s speech will have the same bells and whistles.

Engel, according to his staff, has not decided what to do for the Trump speech. He may not decide until the day of the address. Other Democrats who have previously angled for prime seats have decided to distance themselves from Trump, whose first month in office has prompted outrage from most congressional Democrats.

“I have no desire to sit on the aisle and shake the president’s hand,” said Rep. Bill Pascrell Jr., D-N.J., who has traditionally positioned himself just off the aisle and leaned over his colleagues to get a moment with the president.

Not this time. He’ll be in the chamber, but far away from the aisle.

This is just the latest example of how Trump has scrambled the most basic of traditions in Washington. On Jan. 20, for Trump’s inauguration, a third of House Democrats publicly declared they were boycotting the swearing-in ceremony, led by civil rights icon John Lewis, D-Ga., who declared Trump an illegitimate president because of alleged Russian meddling with the 2016 election contest.

In the Senate, Democrats have turned the normally brisk pace of confirming a new president’s Cabinet into an unprecedented slog – even for less controversial nominees. And this week, thousands of liberal anti-Trump activists have descended on town hall meetings with lawmakers to protest the new president.

Now, even Tuesday’s introduction of the president to a joint session of Congress will be watched for political motives.

Lawmakers and senior Democratic aides said that they do not expect a boycott of the speech, nothing like the more than 60 who refused to attend the inauguration.

Because every lawmaker gets to invite one guest to sit in the gallery above, many Democrats are planning to use that ticket as a form of protest. Pascrell is bringing George K. Yin, a University of Virginia law professor who has argued that Congress has the power to compel Trump to release his tax returns.

Other Democrats will bring children of undocumented immigrants who could be deported if Trump reverses one of Obama’s executive orders, while some plan to bring Muslim religious leaders from their districts in protest of Trump’s travel ban affecting seven Muslim-majority nations, Democratic aides said.

But the “aisle hogs,” as they are affectionately known, are one of the great bipartisan traditions of these presidential speeches. It remains to be seen whether Democrats will back away from that tradition.

Aides to Rep. Sheila Jackson Lee, D-Texas, who like Engel traditionally grabs an aisle seat, did not respond to a request for comment about her plans. She boycotted the inauguration, so if she does take an aisle seat, it could make for a potentially awkward moment.

Those prime seats are not reserved for anyone, so a lawmaker has to arrive early to claim a spot – sometimes a few hours before the speech. Tradition dictates that Republicans sit on the side to the president’s right as he enters and Democrats on the left.

But there’s no rule to it, and one Democratic aide suggested that if the party’s “aisle hogs” give up those seats, Republicans will gladly grab them to be seen back home by conservative voters shaking Trump’s hand.

If that’s the case – if only Republicans greet the president – Washington will look even more polarized on Americans’ television screens Tuesday night than it already has.

In 2008, for President George W. Bush’s final State of the Union address, the first group of people to greet the outgoing Republican president as he entered the House chamber included Reps. Lacy Clay, D-Mo., Al Green, D-Texas, and G.K. Butterfield, D-N.C., along with Engel, Jackson Lee and now-retired Democrats Steve Israel, N.Y., and Jesse Jackson Jr., Ill.

But Trump is different, and no one is sure how to respond to him.

Pascrell all but guaranteed that his side of the aisle will not produce a “You lie!” moment like the one during Obama’s September 2009 joint address on health care, when Rep. Joe Wilson, R-S.C., shouted the accusation during the president’s speech. “He’s the president, duly elected,” Pascrell said of Trump. “He deserves our respect.”

But don’t expect Democrats to just sit there idly if Trump turns his fire on them as he does in his rallies and on social media.

“If he gets too out of order, I’ll walk the hell out,” Pascrell said.

When he entered the chamber last year, Obama looked happy to be greeted by a bipartisan collection of well-wishing lawmakers. With a live mic near him, he made clear that there were some faces that a president should expect to see when they walk down that aisle.

“I’m going to miss you, man,” Obama told Engel.

Turns out, Trump also might miss Engel – and a few other regular faces – on Tuesday night.

(c) 2017, The Washington Post · Paul Kane