SALEM — In a sign of a tightening Republican primary race for governor, Knute Buehler has spent all but $622,000 of his $3.5 million campaign war chest as of May 2.

Along with escalating spending, the two-term state representative from Bend has released ads targeting conservative Sam Carpenter of Bend.

Campaign finance records from the Oregon secretary of state show Buehler spent nearly $1 million alone over two weeks in late April.

Most of the money went for television ads, campaign mailers and fundraising. He has spent at least $16,000 on polling.

Rebecca Tweed, Buehler’s campaign manager, declined to say if the surge in spending was due to concern the race was closer than expected.

“It’s an intense campaign,” Tweed said. “We have been running full force and have no intention of letting up.”

Jim Moore, director of the Tom McCall Center for Policy Innovation at Pacific University, said the heavy spending was likely good and bad news for Buehler.

“All the money you spend increases your name recognition for the general election,” Moore said. “But the timing and amount looks like they got some poll numbers they didn’t like. If the primary is competitive, then they are smart to spend every last dime now.”

Meanwhile, Gov. Kate Brown has the benefits of incumbency, with only token opposition in the Democratic primary.

Brown has been able to keep a high profile by making trips around the state in her official capacity as governor. In addition to her own campaign apparatus, the Democratic Party of Oregon has kept up a heavy drumbeat of anti-Buehler statements. The AFL-CIO has chipped in with an anti-Buehler website. Brown is sitting on $3.7 million cash on hand.

“From the start, she was able to focus on the general election,” Moore said.

Buehler could have raised or spent more than reported — state law allows up to a seven-day lag time to file contributions and expenditures. Buehler appeared in danger of dropping below $500,000 in cash on hand when he received a $90,000 contribution on May 2 from The Pape Group, the Eugene-based heavy industrial equipment sales and leasing company. It’s the second-largest contribution Buehler has received, trailing only the record $500,000 given by Nike Chairman Emeritus Phil Knight last August.

Since launching his campaign last summer, Buehler, a Republican moderate, had focused solely on Brown, largely ignoring the two leading conservative GOP candidates, Carpenter and Naval aviator-turned-motivational speaker Greg Wooldridge of Portland. Neither candidate has raised more than $280,000.

But over the past week, Buehler has turned his attention to Carpenter, who is running a campaign in which he touts himself as the candidate whose politics most reflect those of President Donald Trump. Carpenter uses the slogan “Make Oregon Great Again.”

Buehler’s campaign released a television ad and radio ad equating Brown with Carpenter — saying one raises taxes, while the other does not pay them.

The ads repeat charges that Carpenter has had several liens against him personally and his businesses. Carpenter has said that he repaid all the money he owed and “never declared bankruptcy.”

The ads also highlight a recent tea party denunciation of Carpenter’s campaign manager for race-baiting and homophobic comments. Carpenter does not have “conservative values,” one Buehler ad says.

Carpenter and his supporters have countered that Buehler is a “RINO” — a “Republican In Name Only” — who has criticized Trump and isn’t ideologically fit to be the GOP standard-bearer.

Buehler said last week that if he wins the primary, he expects that at the end of the general election, he will have to raise and spend $14 million to beat Brown. That is $10 million more than he has raised so far.

“That’s the budget,” Buehler said.

If Brown’s campaign raises a like amount, the two candidates could approach $30 million in spending, well above the record $17.7 million spent by Democrat John Kitzhaber and Republican Chris Dudley in 2010. Kitzhaber defeated Dudley by just 1.5 percent of the vote.

Moore says he “remains to be convinced” that the campaign dollar amounts will get that high. If Buehler wins the primary, he will get an immediate infusion of funds and staff support from the state Republican Party, Moore said. But, he said, major national donors will likely wait until after the summer to see if polls show Buehler is within striking distance of knocking off Brown.

“If he is, then the money floodgates will open,” Moore said.

“And if Democrats think they are in danger of losing the seat, they will do the same.”

Buehler said his less doctrinaire approach can appeal to rural and urban voters. A candidate will need Republicans, nonaffiliated voters and disaffected Democrats for the GOP to win an Oregon governor’s election for the first time since 1982.

Moore agrees — with one caveat.

“You won’t be running in the general election if you don’t win the primary,” he said.

— Reporter: 541-640-2750,