DENVER — Colorado lawmakers on Thursday backed off plans to become the first U.S. state to regulate marijuana clubs, saying approval of Amsterdam-style pot clubs could invite a federal crackdown.

It was perhaps the starkest display yet of legal pot states’ uncertainty on how to regulate the drug under President Donald Trump. Alaska marijuana regulators recently delayed planned rules for on-site pot consumption at dispensaries.

Colorado’s measure, which would have allowed users to bring their own pot to clubs, initially had substantial bipartisan support. But lawmakers ultimately sided with Gov. John Hickenlooper, who has warned that bold changes may anger federal drug enforcers.

“Given the uncertainty in Washington, this is not the time to be … trying to carve off new turf and expand markets and make dramatic statements about marijuana,” Hickenlooper told The Denver Post last month.

Colorado and Alaska have cited federal uncertainty about whether clubs would anger federal drug enforcers. U.S. Attorney General Jeff Sessions has criticized the 28 states and Washington, D.C., that do not enforce federal law banning marijuana.

But with no details yet from the Trump administration about how a crackdown would look, states are skittish about making national headlines that could be interpreted as thumbing their noses at federal drug law.

The Colorado pot club measure was amended to remove club regulations, with the remaining bits of the proposal relatively minor. It could face yet more changes before a final vote.

“I’d like to see (a club bill) that goes much further, and that does a lot more, but in a year with Jeff Sessions, a small first step is better than no step at all,” Democratic Rep. Jonathan Singer said.

Sponsors of the legislation said that they had little choice but to back off, leaving Colorado with its patchwork of rules for pot clubs.

Colorado already has about 30 private pot clubs, according to legislative analysts, but they operate under different local regulations and are sometimes raided by law enforcement.

Clubs frequently operate in a similar manner those in states where pot isn’t legal, with small groups meeting up to smoke in a secret location that members sometimes call “Dave’s House,” a reference to an old Cheech and Chong skit.

Not everyone agreed with backing down on the statewide law, saying Colorado is wimping out.

“It only makes sense to allow people to have a place to where they can (smoke marijuana) where it’s controlled and confined,” said Republican Sen. Tim Neville, who sponsored a separate club bill that failed because it would have allowed clubs to sell the marijuana people would smoke, similar to a bar selling alcohol.

“We have legalized marijuana. Where do we want people to use it if not at home? On the street?” he said.

Ballot measures approved by voters last year in California, Maine and the city of Denver would allow either on-site pot consumption or “social use” clubs, but regulations for how those clubs would work haven’t been settled.