The Too-Smooth Cruz Texas’ junior senator moves to nail down his GOP presidential brackets.

And so it begins. Ted Cruz announced Monday, the first major Republican to declare for the presidency. More will soon follow. I am happy because I suffer from a deep, bizarre and pretty American aberration: I love politics. Politics is serious, earnest, crucial, necessary—the venue in which we decide much of our country’s future. Beyond that I love the great game of it—the wins and losses, flubs and failures. The mess, the occasional glory. Even at its most disappointing high politics is the greatness game. Its necessities—caring, taking part, voting—remind us that, as Laurens van der Post once said, we are living not only our own lives but the life of our times.

Every four years political enthusiasts, especially younger ones, say earnestly that this is the most important election of our lifetimes. Many of us have lived through more than one of those. But I can say what this election will most assuredly be, at least on the Republican side: anything but boring. On the Democratic side Hillary Clinton may wind up debating herself on an empty stage with good lighting. But Republicans will have Scott Walker,Jeb Bush,Chris Christie, Ted Cruz, Rand Paul,Mike Huckabee,Marco Rubio and probably John Kasich duking it out. Add Carly Fiorina, and some others. There are some great debaters in that group, serious talents with big accomplishments and very different views. If you want a preview, go to any breakfast, lunch or dinner with conservatives and Republicans in America and hear them argue the case for their guy—while they figure out who their guy is. Boring is not on the menu. “We don’t need another Bush!” “Walker’s the one with guts!” “Kasich will surprise everybody.”

What a heck of a fight this will be.

Ted Cruz and family at Liberty University

Ted Cruz and family at Liberty University

And now, as Ted Cruz often says, let’s get back to Ted Cruz. The latest conventional wisdom is that he is not to be discounted. The latest conventional wisdom is correct.

His announcement Monday at Liberty University was a wow, really brilliant. It’s giving future contenders announcement envy. They’re all going to have to up their game and produce an announcement that’s dynamic, rousing, and shows at least someone is excited about their entry.

It had all the elements. It was a surprise, it was the first of the year, it was beautifully produced—a big bowl of cheering students, some enthusiastically and some because if they had to be there at least they weren’t in class. Mr. Cruz prowled the stage like the showman he is, delivering a full speech without notes. He was like a Sunday morning preacher in a midsize megachurch on a local TV station.

His guiding insight is that only an undiluted conservative can rouse the base to get out the vote that failed to come out in 2008 and ’12. He says he can bring back the Reagan coalition. I don’t know how you reassemble a coalition from 30-plus years ago in a demographically and politically evolving nation, but we’ll see.

A person with intimate knowledge of Mr. Cruz’s thinking told me last week that the senator sees the GOP base in terms of bracketology. A sizable portion of the base is composed of moderates, another of conservative/tea party activists. Then there are evangelicals, then libertarians. Mr. Cruz’s plan is to nail down his own bracket, conservative/tea party. At the same time he is going for evangelicals, big time, which is why he announced at Jerry Falwell’s university and not in Texas. Mike Huckabee is strong with evangelicals, but Mr. Cruz figures that while he can take some of that bracket, Mr. Huckabee won’t be able to get any of the tea party because of his spending record as governor of Arkansas.

Mr. Cruz believes he’s the only candidate who can compete with Rand Paul in the libertarian bracket. He sees a sweet spot with those who are economically libertarian but have doubts about Mr. Paul’s foreign policy.

The moderate bracket is crowded. Jeb Bush, Chris Christie, Scott Walker, Marco Rubio, others—a fight in a phone booth.

Mr. Cruz knows either Mr. Rubio or Mr. Walker could fight him in his brackets. But he thinks they’ll mostly compete in the moderate bracket, where Mr. Bush will get roughed up. Mr. Cruz won’t win moderates, but that underscores his point: A moderate GOP nominee won’t win the general election because parts of the Republican base won’t come out.

Mr. Cruz knows his reputation as the angry, surly face of the dark side of conservatism. He’s the government-shutdown artist, the living answer to the question “What if Joe McCarthy went to Harvard Law?” He says it’s a caricature.

He once noted to me in conversation that when people on TV call him angry and snarling, they never show video to illustrate the point. He says there is no angry, snarling video because he isn’t angry and doesn’t snarl. He never throws mud, he says, and won’t. He sees himself as a happy warrior.

I don’t think the snarling image thing is his main problem. He has two others.

One is much remarked upon. He is 44 and a first-term senator. He entered the national stage less than three years ago, though it seems like longer because he made himself so famous so fast. He talks about Reagan, but Reagan in 1980 had been a union president, two-term governor of a huge state, candidate for the GOP nomination in 1976, and longtime leader of modern conservatism. He had been an executive; he had run things; his accomplishments could be measured.

Mr. Cruz here is not like Reagan. He’s like a first-term senator named Barack Obama, 45 when he announced.

This prompts a major 2016 question: Did Mr. Obama permanently lower the bar? Did his winning and holding the presidency with such limited experience, and his governing in many eyes so unsuccessfully, leave a whole generation of politicians thinking “I can do that!” and “Even I can do better than that!” Or, after Mr. Obama, will there be among Republicans voters a hunger for deeper biography? Is the country in the mood for more on-the-job presidential training?

Mr. Cruz’s second problem has to do with words like sincerity, earnestness, ingenuousness. His conservatism is serious—fully thought through, studied, internalized. But who is he? I think of the comment of one of his fellow conservative senators: “He’s a complete charlatan, you know.” He did the shutdown, said that senator, not because it might work or help but because it served his breakout plan: be the guy who convinces the base he’s the only one they can trust. The senator’s implication: It’s a game to this guy.

It is not hard to notice that every Cruz conversation, every interview, seems to be the rote performance of a speech. In public, and often in private, he moves his hands and face and modulates his voice like a TV pro. Politicians have to be actors, but the trick is to be an actor without being a phony.

Slickness is not a virtue in a politician, and obvious oiliness is a drawback. Mr. Cruz needs some awkward lessons. Maybe he can call Rick Perry.