Looking at the upcoming presidential general election, we recall what ancient cartographers would write on blank parts of maps depicting unknown and unexplored areas of the world:

“Here there be dragons.”

We are sailing off the map of the known political world now, regardless of what prognosticators and analysts purport to understand. The fact that Donald Trump will be the Republican candidate, in a rejection of every wing of the Republican Party power base, says so. And this is reiterated by the fact that Bernie Sanders has amassed so much passionate loyalty in his losing Democratic Party battle against Hillary Clinton.

LettersYour election reflections2016 election2016 Voters Guide: What to know More coverageOpinion and analysis about the 2016 presidential campaign

It might be a once-in-a-lifetime chance to have a different kind of conversation, or it might be the election that changes politics for a lifetime. It might also be an unmitigated train wreck, a cynical and disgusting combination of reality TV and “The Lord of the Flies” in which our national dignity is not a survivor, and the American people are the biggest loser.

But if this election so far has shown one thing, it’s that how our political process plays out is now up to us. For all the talk of Citizens United and corporate power, Trump crushed the GOP candidates supported by big money. He could have raised a nearly infinite amount from fans or spent his own cash pile, but it turned out he needed neither. And while Clinton is going to win more votes than Sanders, he tied her in fundraising by his grassroots loyalists. Multiply his famous $27 average contribution by a huge and energized group of supporters willing to spend, rally and volunteer, and you have a new power base that won’t be silenced.

For decades, presidential elections have generally been about swaying the small set of people who aren’t loyal Democrats or Republicans. It’s all been about romancing the swing voters. But now nearly everyone must be romanced. There are 240 million people in this nation eligible to vote, but in the primaries so far, only 4 percent have voted for Trump and 5 percent for Clinton. The rest either voted against them, or haven’t cast ballots.

advertisement | advertise on newsday

Polls show Trump and Clinton have higher unfavorability ratings than any other presidential nominees in the history of polling. Both have huge factions in their own parties whose votes are not assured. Both have to woo a public that can now react to campaign moves so quickly through social media that it has the ability to shape the race. So Trump must learn that over-the-top personal attacks, such as suggesting Sen. Ted Cruz’s father was complicit in the JFK assassination, will cost him in the general election. He needs to focus instead on real plans for jobs, security, non-fantasy immigration solutions and competent government. And Clinton needs to show that she’s heard what Sanders (and Trump) backers are saying: The nation wants to be inspired by a big vision of a better future. Cautious, establishment, corporatist politics are infuriating a scared and resentful populace.

The maps of unexplored new worlds say, scarily, “Here there be dragons,” but those empty spaces can contain wonderful things, too. It’s up to us, and the candidates, to fill in the blanks properly.

— The editorial board