Four candidates in New Mexico were disqualified from the ballot this week after failing to submit the required number of qualified voter signatures, according to the Secretary of State’s Office.

Among those removed was Republican Christopher Vanden Heuvel of Rio Rancho, who had been seeking to challenge U.S. Sen. Ben Ray Luján in the general election. His disqualification means Luján could appear on the November ballot without a Republican opponent if he defeats a potential primary challenger. It would mark the first time in modern state history that only one major party candidate appears on the general election ballot for a U.S. Senate race in New Mexico.

Also disqualified were Republican Carlton Pennington, who was running in the 1st Congressional District, and Republican gubernatorial hopeful Belinda Robertson of Las Cruces. Additionally, Democrat Thomas Wakely was removed from the ballot, clearing the way for U.S. Rep. Gabe Vasquez to avoid a primary challenge.

Luján may still face a Democratic primary contest depending on the outcome of a pre-primary convention next month. He could also draw a minor party or independent challenger later in the cycle. A campaign spokesman said Luján will continue campaigning while carrying out his Senate duties.

The certification process remains subject to legal challenges, with lawsuits over candidate eligibility permitted through Friday. One Republican gubernatorial candidate, Duke Rodriguez, could face scrutiny over whether he meets the state’s five-year continuous residency requirement. Rodriguez was certified for the ballot despite having voted in Arizona elections in recent cycles. He has stated that the residency issue will not affect his candidacy.

Five Republicans qualified for the gubernatorial primary, including Rodriguez, Rio Rancho Mayor Gregg Hull, state Sen. Steve Lanier, former Public Regulation Commissioner Jim Ellison, and businessman Doug Turner. On the Democratic side, former U.S. Interior Secretary Deb Haaland and Bernalillo County District Attorney Sam Bregman are competing for their party’s nomination.

All statewide offices are on the ballot this year, including the governor’s race, which is open as incumbent Michelle Lujan Grisham is term-limited.