Andy Harris, the Republican congressman who tried to block Washington DC’s legalization of marijuana, may face a tough election challenge as a result. Ironically, it’ll be a primary challenge from his right.

Former Maryland delegate Michael Smigiel told the Guardian that he is planning to run in the Republican primary for Maryland’s first congressional district in April 2016. Smigiel, a former three-term state legislator who narrowly lost a 2014 bid for re-election following redistricting, believes there has to be “a libertarian representing the views of the Eastern Shore [of Maryland]” and that the district needs a congressman who will “stand up to the president and stand up for the constitution” on issues like immigration reform.

But Smigiel saves some of his fiercest criticism for Harris over the capital’s marijuana law, where Harris inserted language in a government funding bill to invalidate a ballot initiative legalizing cannabis in the District. (There is still ongoing debate over whether the language actually has any legal effect.)

To Smigiel, Harris’s criticism of marijuana laws in Washington and Colorado is entirely wrong. He argues that “the 10th amendment says state laws trump federal laws” on things like marijuana. (This is a statement that runs counter to the constitution’s supremacy clause, and supreme court precedent in cases like Cooper v Aaron.) Although Smigiel takes pains to note that Washington DC isn’t technically a state, he thinks the same principle applies. “People should be allowed to spend their money how they wish at the local level,” said the Maryland Republican.

Smigiel also touted his opposition to Obama’s executive orders allowing illegal immigrants to stay in the United States, labeling Obama “a potentate president”, and condemned Harris for voting for a budget that didn’t defund the executive order in the so-called Cromnibus of 2014.

Smigiel also touted his legislative record in Maryland, noting that he helped write the marijuana decriminalization bill that the state actually passed. However, he said he lost credit for it because his partner in writing the bill, former delegate Heather Mizeur, was running for the Democratic nomination for governor against then Lieutenant Governor Anthony Brown. (Smigiel said “I was in the backroom” and described legislative leaders saying: “We can’t let Heather have a bill, she’s running against Anthony.”)

He also noted his efforts on a variety of other issues, ranging from protecting pit bull owners from litigation to working to reduce infant mortality.

Yet Chris Meekins, Harris’s chief of staff, seemed unconcerned about Smigiel, who he dismissed as “not a serious person”. The top aide to the three-term congressman described Smigiel’s bid as an “exercise in vanity”, noting that he “couldn’t win re-election in his own delegate race”.

Meekins also went after Smigiel’s libertarian bona fides, slamming the former delegate’s support for voting for the budget of the Democratic governor Martin O’Malley in 2007, as well as his ties to trial lawyers. “He’s not a libertarian,” said Meekins. “If he were a real one, we’d have a conversation.”

Yet Meekins seems unconcerned that marijuana will be an issue, even if a real libertarian does run. Meekins bragged that Harris did better in his 2014 re-election bid after first trying to overturn the District’s decriminalization of cannabis than he had done two years prior.

Further, it’s unlikely any major conservative groups will get involved in the primary. Harris is ranked as significantly more conservative than the median House Republican on the scorecards of prominent groups like Heritage Action and the Club for Growth. In fact, Harris received support from many of these outside groups when the former Maryland state senator first ran for Congress in 2008 and defeated incumbent Republican Wayne Gilchrest, who was considered to be one of the most moderate members of the GOP caucus. (Although Harris lost the general election in 2008 to a Democrat, he won election to Congress on his second try in 2010.)

Todd Eberly, a professor at St Mary’s College of Maryland, told the Guardian that while the district has become increasingly conservative thanks to redistricting, he wasn’t sure if Harris will “really be vulnerable in a primary like this”. He did find the race an interesting example of how “the politics of marijuana [can] divide conservatives”.

While a social conservative like Harris, who has likened pornography to poison in the past, is deeply opposed to legalization, those from the libertarian wing of the GOP, like Smigiel, see the ban on cannabis as more government regulation.

The question, though, is whether the attempt to overturn Washington DC’s marijuana laws strikes a chord in voters in Harris’s district, which stretches from Maryland’s rural Eastern Shore to conservative suburbs of Baltimore. After all, while Harris’s attempt to thwart marijuana legalization may have deeply angered voters in Washington DC – one insider in municipal politics said a competitive race would definitely “pique the interest” of politically informed city residents – Washingtonians can’t vote for the House of Representatives in Harris’s district or, for that matter, in any other district.