Flying somewhat below the radar of hot legislative races this fall, the 5th State Senatorial District race is an unusual contest for one reason.

That reason is that in a blue-tilting state in an election year that's also seen as favorable to Democrats, it represents a potential GOP pickup, one that could be highly important in future statehouse battles.

Termed-out state Assembly members Lois Wolk (D-Davis) and Greg Aghazarian (R-Stockton) are competing for the seat, which stretches over much of the Sacramento-San Joaquin River Delta and includes both Bay Area bedroom communities like Stockton and college towns like Davis.

Wolk and Aghazarian are competing to replace state Sen. Mike Machado (D-Linden), who is termed out. Republicans tried hard twice before to take the seat, with Machado narrowly winning in 2000 and then-Stockton Mayor Gary Podesto spending $5 million to in an unsuccessful bid to unseat him in 2004.

Money has become a topic in the race this time as well, with Aghazarian outraising his opponent despite her advantage in party registration.

As of the latest reports in late June, Aghazarian had $1.04 million in cash on hand, compared to about $185,000 for Wolk.

That's not a concern, she said.

"Greg got $600,000 from the state Republican Party because they don't have to comply with Proposition 34," she said of a ballot measure that restricts campaign donations. "The Democrats will raise money too."

Wolk said she's not concerned that her background in left-leaning Davis will jar more moderate and conservative voters in the San Joaquin County portion of the district.

"The voters are not that different in Solano County," Wolk said, referring to an area in her 8th Assembly District. "The issues this year favor Democrats. The presidential race favors Democrats."

Wolk pointed out that Aghazarian has played down his Republican Party connections in the campaign, leaving that affiliation off his campaign signs. But she said that while she's worked with other legislators from the other party, Aghazarian hasn't been one of them.

"His record is out of step with the district," she said.

But Aghazarian's campaign manager, Carl Fogliani, said bipartisanship is a trait his candidate is known for.

"We have the candidate with a proven record of results working across party lines," Fogliani said. "He's a good fit for the district."

Fogliani said Aghazarian has been able to raise so much money because contributors of all stripes are happy to support a truly bipartisan candidate.

"He can attract some Democrats, independents and decline-to-state voters," Fogliani said.

It's likely that Aghazarian will need all the crossover and third-party votes he can get. Democrats have a 47-31 percent registration lead in the district, with decline-state-voters making up another 17 percent as of the last report in May.

But Machado's races were far closer, winning with less than 53 percent of the vote both times. A Republican win on November could be a critical wedge for future legislative votes that require a two-thirds majority; the party has kept a role in state policy discussions because of that two-thirds requirement.

Keeping the seat for Democrats would further their goal of eventually having a two-thirds majority without Republican votes.

Wolk said she's confident. "The only way they win is by going negative," she said.

But such a stance is precisely what voters don't want, Fogliani countered.

"Obviously, that's the same kind of partisan rigid thinking that this district abhors," he said. "People see that Greg Aghazarian has a record of delivering for the district. Do they trust him?

"We feel they do, and they will."