President Donald Trump celebrates with Congressional Republicans after the U.S. Congress passed sweeping tax overhaul legislation, on the South Lawn of the White House in Washington, December 20, 2017.

With establishment Republicans increasingly embracing President Donald Trump, the moment certainly seems ripe for him to capture more legislative momentum.

But the details could get in his way, particularly when it comes to infrastructure.

Trump's biggest problems on the issue will come from House conservatives. The White House has already held conversations with the conservative Republican Study Committee and Freedom Caucus to persuade conservatives to support infrastructure spending that they might otherwise see as Obama-style government stimulus spending.

Part of the pitch will be developing ways to say the infrastructure spending pays for itself, including by streamlining requirements for construction projects and developing a dynamic score for the final package that takes into account expected economic growth.

But there's a lot still to be determined, including what the technical details will be, how much detail the White House wants to release and how much the Trump team wants to leave up to the congressional committees to fill in the blanks.

"I don't get the sense that we have had the kinds of serious conversations that it would take," said an administration official, who spoke on condition of anonymity. "The president's inclination is just 'spend money,' while the House is more talking about public-private partnerships."

"The president's view of it is a Manhattan-centric vision of giant bridges and tunnels that people remember. If Donald Trump is building something, he wants it to be huge."

A senior GOP Capitol Hill aide agreed that the plan under consideration and the president's plan might be at odds. "There's an outline of a plan that (White House economic advisor) Gary Cohn has put forward. I'm not sure if Trump is completely on board with that," the aide said, also speaking on condition of anonymity.

"I think the onus is on the administration and the White House in particular to come up with a plan to sell it to members. A giant spending bill might have some issues with conservatives."