For those who hadn't noticed -- most likely younger, unregistered or inconsistent voters -- the post office is delivering a stream of political advertisements along with the standard assortment of bills, letters and junk mail.
It's a clear sign that an election is approaching.
In an increasingly digital age where every serious political candidate has a website, Twitter account and Facebook page, this 20th century means of communication will likely fade into oblivion.
For now, though, old-school snail mail is still seen as a critical path to victory.
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"I do believe that direct mail is going to play a serious role in this election," said Mark Scozzari, a Fresno political consultant.
Of the big four elections -- presidential primary and general election, and gubernatorial primary and general election -- this one, the gubernatorial primary election, historically has the lowest voter turnout.
Low voter turnout, experts say, means that only the most dedicated voters will cast ballots. This electorate tends to be older, own homes, have a landline telephone and read the newspaper that lands on their doorstep.
"Those are not the people getting news via social media," said Tony Quinn, a longtime political analyst in California and former Republican legislative aide. "They're people who have always gotten their political news the same way. They expect to see mailers. They take the time to read the (sample) ballot."
For that reason, everyone from Fresno City Council candidates to Republican gubernatorial hopeful Neel Kashkari are sending out campaign mail. Their targets, political experts said, are first and foremost independent voters who regularly cast ballots.
In this election, Sacramento-based Republican political consultant Matt Rexroad is telling his clients to "send out a lot of mail" -- at least five different pieces.
But he also works to ensure the mail is properly targeted to not only regular voters, but ones who realistically might vote for his client. As such, he looks for hints.
For instance, as a Republican consultant, he knows that a household with two "No Party Preference" voters who both used to be Democrats is probably a waste of money. If he can save 50 cents, he will.
In this election, spending money on direct mail chasing young voters is probably a waste, too.
"Rock the Vote," Rexroad said of the nearly 25-year-old effort to politically engage young voters. "They don't vote."
The true independent voter, the ones truly with no allegiance to a political party, and the one who always votes, "that is the household we always want to hit," Rexroad said.
But every election is different, and in 2012 -- the polar opposite of this upcoming June primary -- experts said President Barack Obama ran a (digital) textbook 21st century campaign that effectively used social media to spread the word, get out the vote and energize a younger electorate.
Republican presidential nominee Mitt Romney "never saw it coming," Quinn said.
Rexroad agreed, saying Democrats in 2012 "turned out voters the Republicans didn't think were there, and they did it using social media."
In the long run, the Obama model will likely become the model used by all candidates, especially as the under 30 crowd settles down, buys a home and has a family.
"Twenty years from now it will be vastly different," Rexroad said.
There are already hints of it now, with some campaigns "microtargeting" voters on social media sites Twitter and Facebook, for instance.
But even though every viable political candidate this year has a digital media presence, the day where that sort of political campaigning rules isn't now.
That said, Quinn said there is one candidate this year who has used social media effectively -- Assembly Member Tim Donnelly, a Republican and Tea Party darling who is seeking the GOP's gubernatorial nomination.
Donnelly and his supporters have used social media -- everything from Facebook to traditional email -- to network about his appearances and have used it to try and rally supporters and attendance at his events around the state, Quinn said.
Donnelly has had no choice, Quinn said. His campaign is chronically underfunded, and running television and radio ads or sending out campaign mail -- especially statewide -- has proved too expensive.
"We'll see if he can get to enough Republicans, because he has no other campaign," Quinn said.
Donnelly, Quinn said, has been able to capitalize on social media via the Tea Party movement to energize his voting base. The better-funded Kashkari is trying to boost his chances with a direct-mail piece that touts: "He's not a politician."
Direct mail from Kashkari, Fresno County District Attorney candidates Lisa Sondergaard Smittcamp and Elizabeth Egan, judicial candidates Steven Smith, Lisa Gamoian and Rachel Hill, and others, shows that for now, it remains a preferred way to reach voters.
A first cousin to direct mail is the "slate mailer," where an organization sends out a direct-mail piece touting a group of candidates that fit its political positions. These can also be profitable, as the organizations let other candidates buy their way onto the mailer.
Scozzari, the local consultant, said he tells all his clients to send out direct mail. This election cycle, he is representing District 4 Fresno County supervisor candidate Steve Rapada, District 1 Fresno City Council candidate Rama Dawar and state Senate Democratic candidate Luis Chavez.
"I'm a direct mail guy," Scozzari said. "I am a dying breed. That's what I use when I'm voting myself."
He said the direct mail that is hitting mailboxes now -- and likely will continue through the June 3 primary election -- still gives candidates the best way "to play your story out. Some of the other stuff is instantaneous, and doesn't give you the ability to deliver a full and complete picture."