Michael Dobie Michael Dobie is a member of the Newsday

Michael Dobie is a member of the Newsday editorial board.

Where do you go from Lee Harvey Oswald?
 
It’s a scary thought. But we’re going to find out.
 
Donald Trump is going to be the Republican candidate for president of the United States. And that was verified on a day when he tried to link the father of the last semi-viable contender standing in his way to the man who killed President John F. Kennedy.
 
This has been some kind of crazy campaign. And it’s going to be a really ugly autumn.
 
When Sen. Ted Cruz suspended his chase after his Indiana shellacking Tuesday night and the Republican National Committee tweeted that Trump was the party’s presumptive nominee, that sealed the deal for the Manhattan billionaire. And Bernie Sanders’ win in Indiana might have perked up the Vermont senator’s spirits but it still leaves him way behind Hillary Clinton for the Democratic Party nod, a gap he is not going to close in any meaningful way. Sanders is not going anywhere and deep down he knows it.
 
So it’s going to be Trump-Clinton, and the only people who saw that steel cage match coming last summer also put down a couple quid on Leicester City’s chances of winning England’s Premier League soccer title.
 
The irony is that of the 20-plus candidates who bravely started out a year or so ago, the two finalists are the ones with the highest negatives in polling. And you know that each is going to do his and her best to highlight the other’s negatives.
 
The pre-game has already begun.
 
Trump had lunch Monday in Indianapolis with writer Edward Klein, who has produced a series of books about Bill and Hillary Clinton filled with innuendo and rumor and mostly discredited. Trump has already called her “Crooked Hillary,” questioned her stamina, and said her success is due only to playing the woman’s card. And when you realize he’s never had the luxury of focusing his fire on only one opponent, you realize there’s no limit to what could be next.
 
After all, Trump referred Tuesday to a National Enquirer story for which no corroborating evidence exists that put Cruz’ father, Rafael, in a photograph with Oswald in the months before JFK’s assassination in 1963. That prompted an epic string of Ted Cruz invective in which he called Trump a pathological liar, a serial philanderer, utterly amoral, and a narcissist. In no particular order.
 
Now, the Clintons are no strangers to in-close combat, either. Their surrogates trashed Monica Lewinsky and some of Bill’s other women, remember? The Clinton machine has been doing its opposition research on Trump, and no one does research like they do. And they’re trying to prepare themselves for the anticipated onslaught.
 
But how do you do that? Was anyone prepared for Trump to say Sen. John McCain was not a hero? A decorated and lionized Vietnam War veteran and prisoner-of-war rightly lionized for his courage and fortitude — not a hero? Because he was captured? Was there anyone who didn’t think that was going to hurt Trump bigtime? Of course, it didn’t.

How did Rubio react to “Little Marco”? Bush to low-energy Jeb? Cruz to “Lyin’ Ted”? Trump criticized Carly Fiorina’s looks, and Heidi Cruz’, too.
 
So get ready for punches and counterpunches, allusions and contusions, a months-long exhibition of mud wrestling. It’ll be Clinton’s flip-flops vs. Trump University, Clinton’s stamina vs. Trump’s business record, Clinton’s lies vs. Trump’s lies, Bill’s infidelities vs. Trump’s womanizing. Trump said Tuesday night that Clinton would be a poor president, and a top Clinton aide said Trump would be too much of a risk. And each says the other is unqualified.
 
All of us know it’s a train wreck that’s coming but we’re riveted. It’s been one wild ride so far, we’ve been alternately thrilled and disgusted, but we seem to be ready for more.
 
And if you’re still wondering whether it can get any crazier, consider this:
 
McCain has said he will endorse the party’s nominee, even if it’s Trump.