Welcome to the 119th Congress. It’s likely to be a momentous one.

For the first time in eight years, Republicans start off the first day of a new Congress with the majority in both chambers and a president of their own party in waiting. The pressure is on for the GOP to deliver on its priorities because, despite the declarations that the party has a broad mandate, history shows that these periods of time — when one party controls all the levers of government and does not have to pretend to be nice to its opponents anymore — are fleeting. 

In the last 44 years, divided government has been the norm, with unified control of Congress and the White House not lasting more than four years, with that occurring only once, from 2003 to 2007. The rest of the time, it’s two years and out, from 1993 to 1995 (Democrats), 2009 to 2011 (Democrats), 2017 to 2019 (Republicans), 2021 to 2023 (Democrats) and that handful of months in 2001, when Republicans had control before one defection in an evenly divided Senate cost them the majority in that chamber. 

The reasons are debatable: Overreach, hubris, overexposure, bad luck, gerrymandered maps. Regardless of the reason, this dynamic is fleeting. 

As Hal Holbrook tells Charlie Sheen in the movie “Wall Street” when Sheen’s stockbroker hot shot character is on a streak: “Kid, you’re on a roll. Enjoy it while it lasts, ’cause it never does.”

Cue the ignition of the budget reconciliation process engines! That set of expedited floor procedure allows the majority to dispense the regular legislative process of pesky filibusters and the like — but it also puts the onus on the majority party to work out its own issues to pass things along party lines. This means the preeminent debates in the 119th Congress, at least initially, will be among Republicans, with the minority largely sidelined. 

The reconciliation process won’t be the only one where Republican-on-Republican debate will be important. 

That will also manifest in the debate over the about-to-breach debt ceiling, which President-elect Donald Trump pushed hard to resolve in last year’s lame-duck session of Congress (No dice). Outgoing Treasury Secretary Janet L. Yellen said last month that the government would need to start taking “extraordinary measures” as soon as this month to avoid defaulting on any government commitments. (How extraordinary is it, though, if these measures are used each time we get close to the debt ceiling?)

The current continuing resolution funding the government expires on March 14. Without a Democratic majority in the Senate and a Democratic president to apply pressure on the debate, as was the case in the last knock-down, drag-out fight over spending a few weeks ago, Republicans might not want to count on Democrats providing too many votes. 

And counting votes will only get more important as we get deeper into the winter months. The House GOP’s official 220-215 margin is the closest in decades. Although former Rep. and current Rep.-elect Matt Gaetz, R-Fla., initially said he would not take his seat in the 119th Congress, who knows? It’s a free country. He could make things interesting. But let’s assume he is not showing up, that puts the GOP at 219. 

These numbers have already made Friday’s vote to elect the speaker very interesting. 

Things will get tighter before they get looser for the House GOP: Reps. Michael Waltz of Florida and Elise Stefanik of New York will leave soonish to take jobs in the new Trump administration. 

Special elections will eventually provide replacements, but not soon enough to factor into a series of close votes in the early times here. As with many things recently, we don’t know when to expect some of the most consequential votes, nor how many members House Republicans will have on any given day. 

Sorry for the cliche, but buckle up.