Former New Mexico Republican Party Chairman Allen Weh will officially launch a bid against Sen. Tom UdallThomas (Tom) Stewart UdallWarren, 2020 Dems target private immigration detention center operators Hillicon Valley: Trump eyes staff shake-up | Amazon taps NYC, Northern Virginia for new offices | What it will mean for DC | Tech firms buck Trump on cyber pact | Defense official warns against hacking back Dem senators pressure FTC to investigate deceptive internet marketing to children 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.