PORTLAND — It’s not every day that Oregon voters get a personal reminder to turn in their ballots from a former president.

But then again, this is no normal election.

So yes, that was former President Bill Clinton urging the voters of Baker City to turn in their ballots last weekend, and check off his wife’s name while they’re at it.

Campaigns across the state, from the Clinton/Obama juggernauts on down are in full get-out-the-vote mode, leaving election officials bracing for what could be the highest turnout in a primary in Oregon history, approaching general election levels of 75 percent.

Think you’ve already gotten a ton of glossy mailers, or automated phone calls, or polite knocks on your door from candidates? Prepare for more — unless, that is, you’ve already voted.

Virtually every serious campaign in the state buys access to a statewide voter database that lets them check off when individual voters have returned their ballot, and who still needs persuasion.

Even those who have already turned in their ballots — about 25 percent of the state, according to the Secretary of State’s office — won’t be safe from the onslaught of political TV commercials.

At this late date, buying TV or radio ads is the easiest — if also the most expensive — way of communicating with undecided voters, and campaigns have given a lot of thought to their final impression.

Democrats deciding between Oregon House Speaker Jeff Merkley and Portland lawyer and activist Steve Novick for their party’s U.S. Senate nomination are being bombarded with images of Merkley’s young daughter talking up her father’s candidacy, and former Gov. John Kitzhaber cheerleading for Novick.

The radio, the medium of choice for candidates with less money to spend, is full of ads like a recent spot from Democratic Secretary of State candidate Vicki Walker, set to a Pink Pantheresque soundtrack, and plays up Walker’s reputation as a crusader, suggesting that shady backroom Salem types are quaking in their boots over her candidacy.

The big campaigns — that would be Clinton and Obama — are bringing in celebrities to press their case, like Sean Astin, of “Goonies” and “Lord of the Rings” fame, who was in Oregon this week to stump for Clinton. Not to be outdone, the Obama folks sent in Dule Hill, who played Martin Sheen’s right-hand man on “The West Wing.”

And they are also making sure that their target supporters know exactly where to drop off their ballots. In Obama’s case, that’s the 18-to-30-year-old demographic: On Friday, the campaign will be shuttling students from the University of Oregon, Oregon State and Portland State to drop-off sites.

Clinton’s campaign, meanwhile, is sending volunteers to senior citizens’ centers to make sure they know where to drop off their ballots. Polls show that she is strongest with voters over the age of 55.

Influential interest groups are also weighing in. Planned Parenthood volunteers are waving signs for Merkley at busy intersections, Basic Rights Oregon, a gay rights group, has sent out full-color mailers touting Secretary of State contender Kate Brown and the Service Employees International Union is pairing Merkley and Obama together on a flier.

Even more importantly, labor unions and other groups with big memberships can send letters explaining and endorsing their choices to thousands of voters at once, a big advantage in local races that have struggled to attract attention.

“So many voters are very clear about how they will vote for president, and unclear about many of the other races,” said Art Towers, political director for the Service Employees International Union, which has poured more than $300,000 into the campaign of John Kroger, its chosen candidate for attorney general. “We’re working to educate them about races they may know less about.”

Then there are the more offbeat strategies: Merkley has been riding the MAX light rail line in the mornings, striding up to bleary-eyed commuters in his pinstriped suit armed with campaign literature.

It’s slow, painstaking work — one voter at a time, no more than 40 or so in an hour. But after countless hours on the phone asking for donations, Merkley is visibly joyful over the face-to-face contact with voters who pin him down on everything from sustainability legislation to mental health care funding.

The personal contact pays off: “I’ve been catching trains and buses here for 25 years, and I’ve never seen a politician here before,” said Mary Ann Sanford, who said she had been planning to vote for Merkley. “It’s nice to see him out here, talking to people who aren’t high-end, people who can’t give him $1,000.”

Novick’s out there, too, waving the metal hook he has in place of a left hand at drivers as they careen over the Willamette River bridges in the morning, and sending his brigades of eager volunteers to work the lines of people waiting to get into the events Clinton and Obama have been holding around the state.

And few campaigns are above last-minute flame-throwing that they hope will sway undecided voters, like congressional candidate Kevin Mannix’s letter to 60,000 Republicans in the Willamette Valley in which he outlined allegations that his GOP rival Mike Erickson had paid for a former girlfriend’s abortion; Erickson has flatly denied the charges and struck back with his own TV ad campaign.

An eleventh-hour flier from the Novick campaign faulting Merkley for not pulling together enough votes to pass legislation to provide health coverage to uninsured children drew howls of protest from health care advocates, who said Merkley had done everything possible to pass the legislation in the face of strong Republican resistance.

“No one worked harder than Jeff Merkley to pass Healthy Kids,” said Maribeth Healey, who directs Oregonians for Health Security and said she has not decided who to vote for in the race.

Novick’s campaign manager, Jake Weigler, countered that the Merkley campaign has trumpeted his legislative leadership, making the point fair game.

“Jeff Merkley’s case for being elected has centered on his ability to bring the parties together,” Weigler said. “This was the central health care item in the 2007 session, Jeff Merkley said he had the votes to pass it and he did not.”

In the end, nothing may motivate voters more than personal entreaties by the candidates themselves. Clinton and Obama will be back in Oregon to make their case before it’s all through; she’ll be in the state on Friday, while he’ll arrive Saturday and leave Sunday.