WASHINGTON ― Donald Trump thinks Republican leaders “love” him, but he may soon find that these warm feelings won’t necessarily translate into unflinching support from Congress.

Some of the most conservative GOP lawmakers, long used to splitting with their party leaders when they deem their actions to be insufficiently conservative, are signaling even before Trump takes office that the incoming president’s agenda could run into roadblocks.

In the House, conservatives are already saying that any proposed infrastructure bill would have to be offset with cuts to win their support.

“If Trump doesn’t find a way to pay for it, then I think the majority of us ― if not all of us ― are going to vote against it,” Rep. Raul Labrador (R-Idaho) said, speaking of Trump’s yet-to-be proposed, potentially trillion-dollar infrastructure bill.

“He’s going to have to come here with some proposals,” Labrador said last week. “And we’re going to agree with some proposals; we’re going to disagree with other proposals.”

If conservatives hold the line on a spending bill, perhaps insisting on at least partial offsets, that could imperil the fragile support of Democrats, who are already on the fence about going along with any portion of Trump’s agenda. Partial offsets for such a large spending project would likely come at the expense of programs that Democrats prefer, and if Trump simply offers up a bill that includes no cuts in order to pay for his infrastructure investments, Democrats would still have the power to join hard-line Republicans and sink the legislation.

It’s a coalition that could emerge soon to stymie Trump: Democrats who think Trump’s plans go too far and conservatives who don’t think they go far enough ― or just aren’t conservative at all.

Conservatives do seem willing to give Trump some leeway. After all, he won partly by casting aside traditional Republican rhetoric on fiscal restraint and promising to bring jobs back to Rust Belt areas. But the Republicans who have spent their congressional careers sounding the alarm on debt and deficits seem unlikely to blindly support Trump’s agenda.

“I don’t think anybody expects him to balance the budget the day he gets in, so he’s got to have some runway for that,” conservative Rep. Thomas Massie (R-Ky.) said last week.

Massie, who recently remarked that Trump wasn’t elected king, suggested that the “fair question” in judging Trump’s budgetary plans is whether the deficit would increase. (The government is currently running at about a $600 billion shortfall every year, with those deficits projected to increase to about $1.5 trillion a year in a decade.)

If Trump increased the deficit, Massie said, “then I think that’s a very dangerous thing, especially for the conservative base.”

House Freedom Caucus Chairman Jim Jordan (R-Ohio) noted that Congress is due to increase the debt ceiling again some time this spring, though the Treasury could use some accounting tricks to probably get the government to the fall. Jordan said he had voted to raise the debt ceiling before when Republicans put forward plans to systematically address debt.

“I’m willing to increase the debt ceiling, if we’re putting in place structural changes that actually get to the problem,” Jordan said.

These sorts of early demands, suggesting that conservatives won’t moderate with a Republican in the White House, could seriously harm Trump’s ability to enact his agenda.

Already, Republicans, including Trump, are backing off from some of his campaign platforms. A 1,900-mile wall along the U.S.-Mexico border looks increasingly like an empty promise. Trump’s statements about keeping popular elements of Obamacare ― like forcing insurers to offer plans to people with pre-existing conditions and allowing young adults to stay on their parents’ health insurance until they’re 26 ― seem impossible if Republicans move forward with their repeal.

If keeping those elements require Trump to keep Obamacare, don’t expect Congress to do his bidding. Republicans fully intend to functionally repeal the law as soon as possible and then later come up with a replacement that may or may not pass.

So if conservatives stay true to their principles and force Trump to govern from the extreme right, Trump may have a hard time delivering on the booming economy he promised ― albeit one that relies on artificial spending at the expense of more debt.

Conservatives seem fine playing spoiler. They recognize that Trump’s brand of Republicanism is not the same kind of ideology that ushered most of their colleagues into Congress. These conservatives, who largely take the same anti-immigration stances as Trump’s base, see themselves as a middle ground between this new faction of the GOP that wants to preserve entitlements and large doses of spending and more traditional Republicans, like Speaker Paul Ryan (R-Wis.), who are pro-trade and would like to see substantive changes to programs like Medicare and Social Security.

“What I’m hopeful for,” Labrador said, “is that we can be the bridge between the Wall Street Journal wing of the Party and the populist wing of the Party.”