Former Rep. Doug Ose is betting $1.6 million of his own money — and counting — that he can defeat a Republican icon in a GOP House primary.

Ose’s opponent in Northern California’s solidly conservative 4th district is state Sen. Tom McClintock, perhaps the most recognized and beloved political figure in California among grass-roots Republicans. McClintock represents a Southern California legislative seat, yet he topped Ose by 32 points in a poll even before he was an official candidate in the GOP primary.

Ose retired from the neighboring 3rd district in 2004, honoring his pledge to serve only three terms.

The winner of the GOP primary will be heavily favored in November to replace retiring Rep. John Doolittle (R). But despite the results of the Moore Information poll paid for by McClintock’s supporters a few months ago, Ose’s team is very optimistic three weeks before the open-seat primary.

“We think it’s going great,” said Ose’s chief strategist, Richard Temple, though he offered no data to back up his optimism. “We are executing our plan as we’ve laid out. Ose’s being well-received and we’re telling voters information they did not know about Tom McClintock.”

But a key component of Ose’s plan has been tried before — twice. And it’s failed twice.

In addition to disparaging McClintock as a carpet-bagging Southern Californian, the Ose campaign has been hitting McClintock for legally accepting the approximately $25,000 per year in tax-free per-diem that California pays state legislators to maintain two households — one in their districts and one in Sacramento, the state capital. California has a full-time legislature, and legislators earn an annual salary of about $116,000.

McClintock has taken the per diem despite the fact that he moved his family to suburban Sacramento about 10 years ago and has not had to pay for two households since 2000, when he first won election to the state Senate.

It’s not a bad line of attack in one of California’s most conservative districts — one where Doolittle has seen his reputation dragged down by ethics issues. Doolittle almost lost his re-election bid in 2006 despite the conservative lean of the 4th district.

But when McClintock’s state Senate GOP primary opponent, then-Ventura County Supervisor Judy Mikels, tried the same approach in 2000, it failed. And when former state Assemblyman Dean Andal, who is running for Congress this year in the 11th district, tried it in the 2002 GOP primary for state controller, it failed again. McClintock won both of those primaries by wide margins.

Temple and his partner, Ray McNally — their firm is the Sacramento-based McNally Temple Associates Inc. — were the consultants for McClintock’s opponent in each of those races, which occurred before the 2003 gubernatorial recall campaign that shot McClintock to statewide prominence.

“The Ose people are using recycled hits against Tom,” said Dave Louden, a Sacramento-based Republican operative who served as a senior political adviser to McClintock in 2000 and 2002 but is not involved in this race. “They failed twice, and they’ll fail a third time.”

With less than a month to go until the June 3 primary and absentee voting under way, Ose’s strong financial advantage over McClintock could prove decisive. The former Congressman recently transferred more than $400,000 to his campaign from his old 3rd district account to go with the $1.6 million in personal funds he’s invested thus far.

McClintock reported raising just less than $316,000 as of March 31 — decent after being in the race for two months but far less than what Ose had at that point. The likely Democratic nominee, retired police administrator and Air Force veteran Charlie Brown, who nearly beat Doolittle in 2006, closed the first quarter with $591,000 on hand.

Ose has used his money to blanket broadcast and cable television in the Sacramento market and flood 4th district mailboxes. On Tuesday, Ose launched a 30-second television spot juxtaposing McClintock’s decision to take state legislative per diem with soldiers fighting in Iraq.

“They travel 7,000 miles from California to Iraq. He travels 14 miles to the Capitol. They’re paid little for the dangers they face; he’s collected over $300,000 in tax-free benefits, but votes against benefits for them,” opens the ad’s ominous voice-over.

El Dorado County District Attorney Vern Pierson (R), described as a veteran, then comes on camera and finishes off the spot by accusing McClintock of voting against benefits for the widows of California soldiers serving in Iraq, although no source for the charges are cited.

“With all due respect to the conservative base that worships the ground Tom walks on, but he’s not perfect,” said one Sacramento-based GOP insider and Ose supporter. “Ose’s message is working.”

Helping McClintock even out his cash deficit is the Club for Growth, a ubiquitous presence in Republican primaries. Rep. Tom Tancredo (R-Colo.), whose push to stop illegal immigration made him a national figure and a hero in some Republican quarters, is also lending McClintock a hand.

The Club for Growth had endorsed former state Sen. Rico Oller (R) over Ose before Oller abandoned his campaign in deference to McClintock. The club then endorsed McClintock, whose conservative fiscal record is a perfect match for its philosophical agenda, and is now advertising heavily on his behalf, including in the mail and on radio and television.

McClintock’s strategy has been to paint Ose as a “liberal” Republican.

In a radio ad set to hit the airwaves on Thursday, the state Senator accuses the former Congressman of personally benefitting from earmarks while he represented the 3rd district. In the ad, a voice-over notes that Ose’s family trust received more than $600,000 in agriculture subsidies while Ose was serving on the House Agriculture Committee. Meanwhile, in a mailer that hit over this past weekend, Tancredo charges that Ose is soft on illegal immigration.

“I was there when liberal Congressman Doug Ose twice voted to give amnesty to illegal aliens,” Tancredo is quoted as saying in the mailer. “He never joined our Immigration Reform Caucus and was never a reliable vote on border control, sanctuary cities or federal requirements for a secure ID.”

The Ose campaign has responded to this mailer with one of its own featuring former California Gov. Pete Wilson (R), who defends the former Congressman’s credentials and says he is tough on illegal immigration. Temple, Ose’s chief strategist, does not think the “liberal” tag is accurate, nor does he believe it will stick.

But the McClintock campaign views this race as a classic philosophical liberal versus conservative contest, with the subtext one of conservative voters who are angry at what they perceive to be considerable overspending by political insiders in Washington, D.C. — particularly those on the Republican side of the aisle.

With this in mind, the McClintock campaign believes Ose’s previous service on Capitol Hill as a member of the Republican majority is a liability, not to mention a 2002 House voting record on economic and social issues that received ratings of 58 percent and 49 percent, respectively, from the National Journal — in the center of the ideological spectrum.

McClintock campaign spokesman Stan Devereux declined to reveal where McClintock stands now in internal polling, although he indicated that the state Senator is well-positioned for victory on June 3.

“Tom is doing quite well,” Devereux said.

This is not McClintock’s first run for Congress. McClintock, then a state Assemblyman, ran for Congress in the old, Democratic-leaning 24th district in 1992, winning a competitive, nine-way Republican primary before losing in the general election.