WASHINGTON (NEXSTAR) — After last’s week drawn-out votes to get Rep. Kevin McCarthy installed as speaker, Monday marked Republicans’ first day in control of the U.S. House of Representatives.

House Republicans say they’re ready to get to work.

“Checks and balances on the Biden administration and working on the priorities of securing the border, inflation, getting this economy back on track,” Rep. Darin LaHood, R-Ill., listed.

He said he’s “optimistic” the party can come together despite the most difficult speaker selection since the Civil War. But bigger battles are on the horizon. Republicans still have to approve a new package of House rules. Republican hardliners who opposed McCarthy’s bid to be speaker negotiated several changes, including allowing a single Republican to call for his removal and greater influence over which bills get a vote.

“It’s not controversial,” Rep. Tom Emmer, R-Minn., said of the rules. “Our members have voted on it once already and I expect it’ll pass.”

But George Washington University legislative affairs expert Casey Burgat said the rule changes guarantee trouble ahead, making it hard to keep the government and economy running.

“Particularly with the debt limit, which both sides, any reasonable person, will be absolutely catastrophic for the U.S. economy. We’re talking jobs, we’re talking recessions, potentially depression, 401(k)s halved, if not more. That matters.”

On NBC News’ “Meet the Press” Sunday, House Democratic Leader Hakeem Jeffries, D-N.Y., said that while he’s willing to work to find common ground, he’s worried the new Republican majority could do real harm.

“What will be a problem is if the American people are held captive over the next two years,” he said.