The weekend will be dominated by back-and-forth on the Iran deal. The administration will argue that some agreement was necessary and this was the best that could be got. They will continue their almost childlike insistence that it proves President Obama is either Ronald Reagan (he negotiates with foes) or Richard Nixon (he reaches out to adversaries).

There will be plenty of serious criticism of the deal, accompanied by a generalized sense that the U.S. probably got taken—because Mr. Obama always wants it too much. As with the opening to Cuba, Mr. Obama put his face on it too early, put his name on it too hard, talked about it too much in public, let his aides give background interviews saying this is a crucial effort, a historic gambit, part of the president’s visionary legacy. The adversary sees this, the need and the want—they watch the news too!—and proceeds accordingly.

Mr. Obama is an odd one in that when there are rivals close by, in Congress for instance, with whom he could negotiate deals, he disses them in public, attacks their motives, yanks them around with executive orders, crushes them when possible. But when negotiating with actual tyrants he signals deference, hunger. I leave it to others to explain what it means when a man is bullying toward essentially good people and supplicating toward bad ones. But the sense is he always wants it too much and is consequently a poor negotiator, and this will have some impact on U.S. and world reaction.

Wisconsin Governor Scott Walker at a Harley-Davidson dealership

Hillary Clinton has given her tentative support. The day before the deal was announced she gave a big economic speech, at the New School in New York.

I wanted to think along with it, but Mrs. Clinton doesn’t give you much to think to. She offers policy clumps wrapped in general sentiments. There was policy jargon—“consumer economy,” “quality, affordable child care,” “paid family leave,” “our fiscal outlook is sustainable.” In the tired rhetoric department there were “currents of change” and getting “our country moving.” There were a few fleeting shots at Republican candidates, which provided the speech with a kind of leavening cynicism.

She seemed at times to knock Mr. Obama, or at least distance herself from him. Wall Streeters who tanked the economy in the late 2000s got off with “limited consequences—or none at all.” Who’s been in charge since 2008? She made two references to rising health-care costs. I thought we took care of that.

There was a thought worthy of unpacking, which had to do with the “short-termism” that dominates CEOs’ thinking; they are enslaved to a “quarterly capitalism” that leaves them focused on the share price and the next earnings report at the expense of longer-term investment. This is true: They’re all squeezing too tight and missing the big picture because in the general rush of demands they can’t afford to see it. I’m not sure what a president can do about it, but it’s not bad to talk about such things.

Along the way she smuggled in a campaign theme: “I want to have principled and pragmatic and progressive policies.” I suspect we’ll be hearing more of the three P’s.

There was a nice thought nicely expressed: At its best, “public service is planting trees under whose shade you’ll never sit.” That was pretty.

It was a pointillist policy-dot speech meant to add up to a portrait of meaning. The meaning was clear: More progressivism, please. Also: There’s little substantial difference between Bernie Sanders and me other than that Goldman Sachs likes me, which only proves my range. The left doesn’t have to bolt away.

A concern for her campaign has to be Mrs. Clinton’s robotic delivery, as if she’s never there in the moment but distanced from herself. As if she’s thinking: I don’t fully believe this, but more important, do I seem to believe it? She seems to be overcoached by people who keep telling her to be natural. But why would someone in public life for more than 30 years need to be instructed in naturalness? I don’t understand her discomfort and wonder what it suggests or portends. You can argue she’s a strong leader; she may be the next president, she may be the acknowledged head of her party, but she is a poor campaigner—a poor giver of interviews and speeches, which is now most of what campaigning is. At the end of the day this will mean something.

Meanwhile, Scott Walker announced in Waukesha, Wis. There is still something fresh and awake about him. He’s not all dinged up and slump-shouldered, even though he’s been a target for so long. His subliminal message—actually, it’s liminal—has two parts: I wasn’t born into it, I’m normal like you—but I’ve achieved a great deal, maintained my seriousness, and been a brave governor.

He made his announcement in the increasingly popular casual manner, in shirt sleeves with an open collar and casual slacks. They’re all trying to express intimacy by removing barriers—podiums, teleprompters. But that’s superficial. You can make a connection in a suit behind a podium if you sound as if you’re thinking and speaking honestly and with depth. All this physical symbolism has gotten carried away. John Kasich is next. I’m hoping he won’t announce in a T-shirt and underpants.

What is most interesting about Mr. Walker is that he has remained in the top tier, often in the top three, while being less in the public eye recently than other candidates. His years as embattled Wisconsin governor have given him a hold on the Republican imagination. As he spoke I thought: He’s from the Republican wing of the Republican Party—blunt, direct, unadorned, Midwestern. His message was workmanlike: “I know how to fight and win.” He is a reform conservative, believes in federalism, is hard-line on foreign policy: Mr. Obama says climate change is the greatest threat to future generations, but “the greatest threat to future generations is radical Islamic terrorism.” Vladimir Putin, like Lenin, probes his adversaries with bayonets: “If you encounter mush, push; if you encounter steel, stop.” Mr. Walker will run hard on his Wisconsin record: “We lowered taxes by $2 billion. In fact we lowered taxes on individuals, employers and property. In fact, property taxes are lower today than they were four years ago. . . . How many governors can say that?”

All this will make him highly competitive for the nomination. Is it suited to the mood of the nation in the general election?

Mr. Walker, Jeb Bush, Marco Rubio, Carly Fiorina, Ted Cruz, soon John Kasich: They are going to be flooding the hustings very soon, and they’re going to hit Republicans on the ground as an embarrassment of riches—interesting, accomplished figures, all with a case to make. They’ll have the money to last because they pretty much all have rich backers. It is going to be hard for Republicans to make up their minds. This primary is going to go longer and end later than anyone knows.