Some of President Donald Trump’s biggest fans in Congress — members of the conservative Freedom Caucus — are worried he’s taking gun control too far.

As the deadly shooting at a Parkland, Florida, high school, which killed 17 and injured more than a dozen others, sparks a national conversation around gun control, the White House is pushing Congress to actually pass gun control measures. But a group of the House’s most conservative and Tea Party-sympathetic lawmakers are concerned the momentum might be headed in the wrong direction, and they’re cooking up alternatives to rein in the president.

“We’re pretty sure they’re going to do something just for the sake of doing something,” Rep. Scott Perry (R-PA) said, leaving a raucous debate between Freedom Caucus members on how to address the White House’s gun control push. Rep. Mark Sanford (R-SC) said members were shocked by where Trump was willing to go on gun control.

So far, Trump has spoken in support of more comprehensive background checks and signed a memo for his administration to ban “bump stocks,” devices that make semiautomatic weapons work like fully automatic ones, without Congress’s approval.

He’s floated giving police the authority to temporarily confiscate guns from those reported to have violent or threatening behavior or who have mental illnesses, and said he would consider raising the minimum age for purchasing certain assault rifles from 18 to 21. He’s also suggested arming school teachers.

Many of Trump’s positions signal a clear break from the traditional Republican talking points on mass shootings, which typically steer away from any actual gun control-related measures. Now it appears the Freedom Caucus and its chair, Rep. Mark Meadows (R-NC), are strategizing how to steer Trump back in their direction, away from gun control and toward armed policing and a focus on institutionalizing those with mental illnesses.

“There was talk about how do we give him meaningful alternatives,” Sanford said.

This strategy has been successful in the past. Trump has been known to engage these conservatives, even if it risks killing the policymaking effort altogether. It wasn’t too long ago when Trump voiced support for Democratic-driven immigration policy before turning back to propose a kitchen sink of immigration restrictions spun up by Congress’s archconservatives — a hardline position that ultimately tanked negotiations in the Senate.

If conservatives succeed in dominating the gun control conversation, this could spell trouble ahead for any hopes of legislative action.

Conservatives have problems with a lot of Trump’s gun control positions

Going down the list, Freedom Caucus members have found issue with almost all of Trump’s gun control positions.

On his decision to use executive power to ban bump stocks without Congress’s approval: “I would recommend him against that,” Rep. Joe Barton (R-TX) said.

What about Trump’s consideration of raising the minimum age for buying assault rifles?

“I don’t see that as being a starter,” Meadows said. “I think that’s a little bit too controversial,” Barton echoed.

What about the narrowest reinforcement of existing background check rules — the Fix NICS Act — which wouldn’t actually establish any new gun control measures but just make sure federal and state agencies complied with current law?

There’s a “due process issue,” Meadows said. “Somebody saying you have a mental health issue and you actually having a mental health issue are two different things... What constitutes a mental health concern?”

Current federal law requires agencies to report certain convictions and for adjudicated mental illness to be uploaded to the instant background check database. Conservatives have raised concerns that some agencies can formally declare “mental illness” without due process.

With every mass shooting, Republicans have been careful to avoid conversations around expanding background checks or imposing any kind of gun control measures, outside of arming more people.

After the Parkland shooting, House Speaker Paul Ryan focused on past legislation on mental health issues, despite the fact that Republicans actually made it easier for people with mental illnesses to purchase guns last year. It’s the same line he used after the Las Vegas massacre.

Asked about the Fix NICS Act, Barton instead pivoted to talking about the decline of mental health institutions and the possibility that medications prescribed to address mental illness “really mess people up” and are “one of the reasons there has been an increase in these mass shootings” — recounting a belief held by his colleague Rep. Gary Palmer (R-AL).

Meadows floated one idea to give tax credits to volunteers, like retired police officers, who want to offer armed security outside schools.

Trump has a habit of listening to conservatives. Is this time different?

The Freedom Caucus has established itself as an essential player in policy negotiations under Trump. The president has routinely engaged the conservative hardliners on everything from health care to immigration.

But on guns, he has put the most conservative members of Congress in a difficult position: These lawmakers both represent districts that fervently support Trump and find themselves ideologically divided from him.

“Politics makes for the strangest of bedfellows,” Sanford said of the predicament; he has spoken openly against Trump, yet he sees himself closer to the president on the gun issue than most of his Freedom Caucus colleagues do.

This isn’t the first time conservatives have been faced with this dilemma. Trump, who engaged the far-right hardliners during his presidential campaign, isn’t an ideologically consistent conservative after all.

But the Freedom Caucus knows its power. As the chair of a cohort of roughly 40 men who make up the House’s most conservative faction, Meadows wields enough votes to stop any Republican-led legislation in its tracks. And he has a direct line to the president if things don’t go his way — leverage he has used in the past to make an unpopular Obamacare repeal bill move further to the right in the House and reinforce the White House’s hardline position on immigration.

Meadows, of course, brushes off the idea: “The president instructs me more than me instructing the president,” he said.

But that hasn’t stopped his group from brainstorming alternatives — any of which could derail the direction Trump is pushing Congress in.

Their efforts might already be working. CNN’s Jim Acosta reported Monday night that Trump is already backing away from increasing the minimum age to purchase assault rifles.