Hillary is the only thing holding Democrats together, and Bushes always break the Republican Party. Both parties are nervous about 2016

Governor Jeb Bush

Former Florida Governor Jeb Bush

The 2016 presidential campaign is here, pushed up prematurely by the Hillary Clinton email controversy. When a major candidate of a major party has major trouble, the election moves more sharply into focus.

Apart from Mrs. Clinton, small stories have begun to shoot up like flares.

Wisconsin Gov. Scott Walker shied away from the accomplished and interesting Liz Mair, who had agreed to be digital strategist in his social media operation. She had tweeted some indiscreet, funny and provocative things about Iowans—the word “morons” was involved—and is also moderate or liberal on various social issues. She was not signing on as a domestic or foreign-policy adviser, but even campaign staffers now, in political oppo culture, are the target of full Internet body frisks.

There was something sad in the story. Now of all times you want to see candidates include a wide variety of voices, including irreverent and especially creative ones. A diverse party with everyone in on the fight, no loyalty oaths or litmus tests, is what is needed. But that kind of decision probably wouldn’t come from a candidate whose breakout plan begins with the word Iowa.

Mike Huckabee has, amazingly, been revealed by the New York Times as hawking, for money, an unorthodox diabetes cure in an Internet infomercial. I watched it. He comes across as a smooth, friendly huckster or a teddy-bearish snake-oil salesman, which is not how a presidential candidate would normally want to look. Once a young journalist, looking at a photo of Paul Ryan in gym shorts and sleeveless T-shirt with his cap on backward and lifting barbells, said, musingly, “That’s a real congressman move.” Hawking magical elixirs is a real Arkansas governor move.

The president has jumped into the strangeness fray by musing aloud that mandatory voting in the United States would be a good idea. “It would be transformative if everybody voted,” he told an audience in Cleveland. Yes, it would. It would mean a lot of people who aren’t interested in public policy and choose not to follow it would suddenly be deciding it.

The way it is now, if you aren’t interested—and you have the right not to be interested—you don’t have to vote. If you are interested, you pay attention, develop political views, and vote. Making those who don’t care about voting vote will only dilute the votes of those who are serious and have done their democratic homework.

Most of us are moved by the sight of citizens lined up at the polls on Election Day. We should urge everyone to care enough to stand in that line. But we should not harass or bother those who, with modesty and even generosity, say they are happy to leave the privilege of the ballot to those who are engaged. Mandatory voting is, so far, the worst and most mischievous political idea of the year, and deeply eccentric.

I detect more than the usual amount of uncertainty and angst among the leadership of both parties this year, and it is due to doubts about their putative front-runners.

Democratic establishment angst is composed of obvious and less obvious elements. Obvious: They worry Mrs. Clinton’s email-gate will linger, and they’re afraid of more scandals tumbling out of the Clinton Foundation closet. They fear the constant regurgitation of old scandals. They’re afraid they’ll have no sway when future embarrassments and controversies come. She’s Hillary, she does it her way, she keeps it close, it’s a tight circle.

Less obvious: She’s all they have.

By that I don’t mean there is no one else who can run. It’s a shallow bench, but a bench. I mean that for all her flaws Hillary Clinton is the only major Democrat who can keep the Democratic Party together in this cycle.

Without Hillary the party will probably lurch left. And if it lurches left it’ll probably lose the general election. Democrats will break up into left-progressives, way-left-progressives, populists of different stripe, older moderates and centrists. The left is no longer passionate about Mr. Obama because he is not left-wing enough. Hillary Clinton holds the party together with her Hillaryness—her popularity with the base, her connection to the Clinton years, her sex. The idea of the first female president in a party increasingly preoccupied with identity and gender politics is a powerful ideological glue.

Hillary, to the general public, comes across as centrist. In part this is because she is associated with her husband’s ultimate moderation, and in part because she has grown more moderate over the years, at least in the sense of playing ball with various entrenched powers. She is certainly hawkish. Her popularity and persona will keep her party seeming centrist, even if she inches to the left to appease sizable parts of the base, and to show her heart is still with them.

But I think an untold story of 2016 is that the Democratic establishment is desperate when Mrs. Clinton is in trouble because without her they see a fracturing of their party.

We focus on the GOP and its dramas with what is called the far right. We pay no heed to the Democrats and their dramas and challenges from what is never called their far left.

There’s a balancing angst among many Republicans. It is connected to the fact that Jeb Bush is broadly considered a front-runner, if not the front-runner. And at the end of the day Bushes always break the party.

George H.W. Bush didn’t mean to but he did, in 1990, when he gambled that the economy would rise and its rise would justify his rescinding of his no-new-taxes pledge. Instead he got a recession. Thus was born Pat Buchanan’s candidacy for the presidency and what in retrospect was the first iteration of the tea party. Mr. Bush lost the election.

George W. Bush broke his party after his 2004 re-election, in part with his immigration proposals and the way he advanced them, with aides insulting his GOP opponents—“nativist,” they said—and, in the end, by two unwon wars. Add the crash and the presidency was closed to the Republicans for at least eight years. Mr. Bush gambled that the wars would be victorious, that the party that loved him would march to the banner of an immigration agenda that did not take their legitimate anxieties into account. He left a party more broken, less a whole.

But what’s different about Jeb Bush is this: His father and brother surprised the base with their decisions after they had won the presidency. Jeb is declaring before he wins that he will take particular stands at odds with many in the base—for comprehensive immigration reform, for the Common Core.

He said the other day he’s doing it because he has “a backbone.” That’s a strut, not an argument. It will be interesting to hear the argument. He should meet—publicly—with anti-Common-Core parents, take every question, answer every criticism, and make his case with data and through the prism of experience.

Same with immigration. Take all comers.

That would show backbone. That will get others, not just him, saying he has it.