Former New Mexico Republican Party Chairman Allen Weh will officially launch a bid against Sen. Tom UdallTom UdallDems, greens press Trump administration on methane rewrites Overnight Regulation: House passes bill to roll back Dodd-Frank | Sage grouse back in the spotlight | GOP chair won't back Glass-Steagall revival Overnight Tech: FCC disputes reporter's account of 'manhandling' incident | Verizon to cut 2K jobs at Yahoo | Russians used spyware on Instagram | Virginia moves on 5G networks MORE (D-N.M.) on Thursday, according to the Santa Fe New Mexican.

Weh, a businessman who finished second in a five-way gubernatorial primary behind New Mexico Gov. Susana Martinez (R) in 2010, will announce his candidacy via Web video. He's long been expected to run for the seat.

Udall is viewed as safe in the Democratic-leaning state. But Weh has the ability to self-fund much of his campaign — he spent $1.6 million of his own money in his race against Martinez — and could force Udall to spend more money than he otherwise would have had to.

Libertarian-leaning Republican attorney David Clements is also in the race.