Mitt Romney’s challenge heading into the long summertime slog before the convention? How to engage the majority of voters who aren’t tuned in to the campaign yet.

For nominees who play it smart, there’s a long list of boxes to check off to ensure all the pieces are in place for the fall: raising money, picking a vice presidential candidate, prepping for the convention and building a nimble ground game in battleground states.

“You campaign particularly in the key states, and pay attention to the local media,” said Sen. John McCainJohn Sidney McCainLawmakers worry about rise of fake video technology Democrats put Dreamers and their party in danger by playing hardball Trump set a good defense budget, but here is how to make it better MORE (Ariz.), the 2008 Republican nominee.

Top advisers to previous nominees from both parties said it’s the incumbent’s game during the slow summer months, both because the incumbent can control the message and because of the head start in building a large-scale operation.

Asked about the best use of the nominee’s time in the months before the conventions, Stacie Spector, a senior adviser to President Clinton’s 1996 reelection campaign, offered two words:

“Raise money.”

The second-most important thing a nominee can do? Raise money, said Spector.

For Romney, there’s a longer list of key tasks that must be delicately and deftly carried out before he can focus full-time on making his case against President Obama.

“The first thing they’ve got to do is the vice presidential nominee. Let’s get them vetted — and vetted thoroughly,” said Craig Smith, a former speechwriter for President George H.W. Bush. “That leads to No. 2, which is how to make the convention interesting.”

In 1988, polls showed Bush 13 to 17 points behind heading into the Republican National Convention. But his well-received “thousand points of light” acceptance speech, where Bush debuted the phrase “Read my lips: No new taxes,” changed the game for his campaign.

“We came out 10 points ahead,” said Smith. “If you hit it right, it can really change everything.”

Romney and Obama can find clues for hitting their convention speeches out of the park in the torrent of polling that both campaigns are inevitably conducting. President Nixon used that strategy in his highly successful convention speech in 1968, Smith said.

“Where they had unanimity in poll numbers, Nixon articulated very specific solutions,” he said. “Where there wasn’t unanimity, he focused on the problem and glossed over the details — like ‘peace with honor’ to talk about Vietnam.”

Romney also has more work to do in building the kind of robust, large-scale operation that Obama, lacking a primary fight, has had more than a year to put together. There are aides to be hired, offices to be opened, voter lists to be culled and fundraising operations to be bolstered.

“There’s this moment of pause after you secure the nomination, then a massive sprint to try to scale to 10 times what it was during the primary,” said Chip Smith, the deputy campaign manager for then-Vice President Al GoreAlbert (Al) Arnold GoreJoe Lieberman: We’re well beyond partisanship, our national government has lost civility Trump doesn't start a trade war, just fires a warning shot across the bow Dems face hard choice for State of the Union response MORE’s campaign in 2000.

Obama’s other advantage comes from his ability to set the tone of the debate by focusing on the successes of his first term while simultaneously conveying the gravitas of the man currently running the country, said Spector, who advised Gore’s campaign in addition to Clinton’s.

“Experience, confidence, a clear, inspired vision, compassion and connection will win out,” said Spector. “The summer before any election is about cementing that perception in the minds of voters.”

But lest either candidate let the summer grind lull him into thinking he can wait until after the convention to really turn on the heat, it should be noted that voters are tuning in earlier and earlier every cycle, said Christian Ferry, deputy campaign manager for McCain-Palin in 2008.

“Traditionally we said campaigns really get started after Labor Day,” he said. “I’m not sure that’s true anymore.”

Frustration with the economy and the slow pace of recovery has more Americans questioning what the White House can do to make a difference in their lives. And more states are offering early voting than in the past, with some extending the period of early voting to 30 or more days before the election, Ferry said.

“The days of everyone going to the election booth on the first Tuesday of November and casting a vote are over,” he said.