Fair or not, all three — Clinton, Trump and Cruz –– stir intense feelings and bring out the hatred of their enemies. None of them can win in November based on positive qualities. They can win only by jacking up their opposition’s negatives even higher.

The only candidates with positive leaning ratings, at least in some polls, are underdogs Democrat Bernie Sanders and Republican John Kasich, and that’s largely because they’re not seen as threats. But if either rises to serious contention, watch their negatives jump, too.

While this year’s nomination contests have been nasty, raucous affairs, just wait for the general election. No matter who the nominees are, it will be fraught with even more opportunity for malevolence. Super PACs will blossom like Chairman Mao’s hundred flowers. Billions will be spent on vicious attacks. Debates and ads will be packed with allegations and smears.

It will be a campaign with all the charm of a Mafia hit. The winner will be the one who crawls across the finish line first — debased and exhausted.