Former San Joaquin Valley Rep. Richard Pombo will formally announce his comeback bid today, igniting a heated competition to replace retiring Rep. George Radanovich, R-Mariposa.

A one-time chairman of the House Resources Committee, Pombo is a proven fundraiser who's admired by his fellow ranchers but loathed by environmentalists. His candidacy puts the 19th Congressional District race on the national political stage.

"I've talked to a lot of people over the past week," Pombo said in an interview Monday. "A lot have been encouraging me to do this because of the situation we have in the Valley, what I have done in the past and what I could do now."

Pombo is entering the race a week after Radanovich announced he will retire after this year because of his wife's illness. Ethie Radanovich was diagnosed three years ago with ovarian cancer, and in recent weeks has been in and out of a hospital.

State Sen. Jeff Denham of Atwater and former Fresno Mayor Jim Patterson already have announced their intentions to run for Radanovich's seat. Former California Secretary of State Bill Jones and current Fresno City Councilman Larry Westerlund also are mulling potential runs.

Pombo's political potential was demonstrated even when he lost his 2006 re-election bid in the 11th District, during which he raised $4.5 million. He subsequently joined Oregon-based Pac/West Communications as a senior partner, but he'll likely still be tapping his former colleagues for support.

"He'll be very strong," said Johnny Amaral, chief of staff to Rep. Devin Nunes, R-Visalia. "His politics fit that district extremely well, and he has an ability to raise money."

Whichever Republican wins the June primary will be the prohibitive favorite in the November general election. Republicans enjoy a 44 percent to 37 percent voter registration advantage in the district that includes all or portions of Stanislaus, Madera, Mariposa, Tuolumne and Fresno counties.

A Tracy native who turns 49 on Friday, Pombo does not reside in the congressional district he hopes to represent. Pombo never represented any of the 19th Congressional District's counties during his prior House service, and Amaral acknowledged in particular that Pombo "is going to have to introduce himself to the Fresno area."

Pombo plans to start doing that today, when he announces his candidacy on Fresno-based KMJ radio.

"With me in, it changes things," Pombo said. "I spent 14 years representing the Valley. I would stack my conservative credentials up against anybody. Look at my record. I have a record of actually doing things."

As chairman of the House Resources Committee for four years, Pombo prevailed in some areas such as speeding up the thinning of overgrown forests. He failed, though, in his high-profile effort to rewrite the Endangered Species Act even when Republicans controlled both the House and Senate.

Though he was popular among the Valley's ranchers, farmers and developers - as well as with some Democrats such as Rep. Dennis Cardoza of Merced - Pombo's crusade to revise environmental laws prompted environmental groups to spend several million dollars to help defeat him in 2006. Defenders of Wildlife President Rodger Schlickeisen said "voters should remember that Richard Pombo was booted out of office by voters," and Democratic campaign professionals made clear their intentions to bring up past controversies.

'Richard Pombo defined pay-to-play politics and ethically challenged behavior, all of which was soundly rejected by California voters,' Democratic Congressional Campaign Committee spokesman Andrew Stone said Monday. "We can expect more of the same this time around."