Former New Mexico Republican Party Chairman Allen Weh will officially launch a bid against Sen. Tom UdallTom UdallWhat veterans have to lose in Trump’s national monument review Overnight Energy: House passes Russia sanctions deal with oil, gas fix Dem bill would ban controversial pesticide 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.