One of the big questions in US politics over the past few months has been why Kamala Harris has so much difficulty talking about the policies she herself has adopted and decided to run on. Is it part of some ingenious secret strategy, an example of her playing checkers while we observers play chess? Or does it reflect the weakness of a candidate who much of her own party was nervous about elevating to the top of the ticket?

We may have gotten our answer in last night’s vice presidential debate. Harris’s running mate, Minnesota governor Tim Walz, put in a performance that was far from the smooth and polished one you’d expect from a decades-long political operator. He mixed up Iran and Israel several times, for example, and at one point said he had “become friends with school shooters.” Nevertheless, he capably and effectively both made the case for Harris’s agenda and explained how what Donald Trump and J. D. Vance planned to do would be disastrous for voters’ lives.

Walz is where he is right now in large part thanks to his communication skills, and there’s a lot that not just wonky liberal technocrats but leftists can learn from his rhetorical style. Throughout the night, Walz was able to put complicated, esoteric concepts and policy details into everyday terms that just about anyone can understand, and frame them as matters of fairness and basic common decency.

Here he was, for instance, on Harris’s plan to bring down housing costs and the efforts taken under Biden to limit the extortionate price of insulin that was driven by corporate greed:

There’s three million new houses proposed under this plan, with down-payment assistance on the front end. To get you in a house. A house is much more than just an asset to be traded somewhere; it’s foundational to where you’re at. And then making sure that the things you buy every day, whether they be prescription drugs or other things, that there’s fairness in that. Look, the $35 insulin is a good thing, but it costs $5 to make insulin. They were charging $800 before this law went into effect.

Here he was on the lopsided US tax system, where those with wealth and connections can use loopholes to make sure they pay less in taxes than ordinary workers:

I ask you out there — teachers, nurses, truck drivers, whatever — how is it fair that you’re paying your taxes every year and Donald Trump hasn’t paid any federal tax [in the] last fifteen years, in the last year as president? That’s what’s wrong with the system; there’s a way around it. And he’s bragged about that. We’re just asking for fairness in it, and that’s all you want.

Walz took a similar tack in response to Vance’s blaming of government regulations for high house prices, reminding viewers in concrete terms that there’s a good reason those regulations exist:

Whenever we talk regulations, people think they can get rid of them. I think you want to be able to get out of your house in a fire. I think you want to make sure that it’s fireproof and those types of things.

Here is how Walz assailed the GOP’s planned abortion restrictions and explained why Trump’s attempt to square this deeply unpopular circle — by saying that all he was doing was letting states decide what worked best in their unique, individual cultures — didn’t make sense:

It’s going to make it more difficult, if not impossible to get contraception and limit access, if not eliminate access, to infertility treatments. For so many of you out there listening, me included, infertility treatments are why I have a child. That’s nobody else’s business. But those things are being proposed, and the catchall on this is, well, the states will decide; what’s right for Texas might not be right for Washington. That’s not how this works. This is a basic human right. . . . The fact of the matter is, how can we as a nation say that your life and your rights as basic as the right to control your own body is determined [by] geography?

And here is Walz explaining what Trump and Vance’s plan to repeal Obamacare and return to the status quo prior to the law’s passage — of putting healthy and less healthy people into different insurance risk pools, so that the young and healthy pay lower premiums — would mean for people in practice:

What that means to you is you lose your preexisting conditions. If you’re sitting at home and you got asthma, too bad. If you’re a woman, probably not. Broke your foot during football, might kick you out. Your kids get kicked out when they’re twenty-six. . . . What they’re saying is, if you’re healthy, why should you be paying more? So what they’re going to do is let insurance companies pick who they insure. Because guess what happens? You pay your premium. It’s not much; they figure they’re not going to have to pay out to you. But those of you a little older, gray, you know, got cancer? You’re going to get kicked out of it. That’s why the system didn’t work.

Much of this is genuinely impressive political rhetoric. The problem is, it’s at the service of an unambitious campaign of small, incremental change, even corporate appeasement, that many of us hoped the post-2016 period had eliminated for good.

Imagine if this rhetorical style was put toward, say, reminding Americans about the nonsensical, bureaucratic cruelty of private insurance, and how it would be better to all but eliminate it and replace it with a Medicare for All system. (Walz accidentally gestured at the ease of such an argument, when he said that “making sure the risk pool is broad enough to cover everyone, that’s the only way insurance works.”)

Walz did a good job of explaining how climate change impacts people throughout the United States, especially farmers, and why the Inflation Reduction Act (IRA) is important. “These are not liberal folks,” he said. “These are not folks that are Green New Deal folks. These are farmers that have been, drought one year, massive flooding the next year. They understand that it makes sense.”

But imagine if, instead of being used to simply defend the gains of the IRA and remind people that climate change is already wreaking havoc on Americans’ lives, this rhetorical style was deployed to make the case that climate change was the greatest national security threat facing the country and planet, and that combating it demanded a society-wide mobilization the likes of which hearkened back to the country’s greatest era?

No, instead we have yet another campaign that revolves around preventing Obamacare from being repealed as US households continue getting screwed over and driven to bankruptcy by their insurers under it, and around pretending the IRA alone is enough to deal with climate change, or even that the country can continue drilling and burning fossil fuels at record levels. Neither candidate even bothered talking about raising the pitiful US minimum wage, which just four years ago was not only central to the Democratic campaign, but marked a major point of disagreement on the debate stage.

Walz mentioned that he went to college on the GI Bill, but unlike when he brought up veteran’s home loans to make the case for Harris’s down-payment assistance plan, there was no accompanying case for letting all Americans have the same possibility of debt-free higher education — because free college and the debt that universities currently burden young people with have completely dropped off the Democratic agenda. The proposal for rent caps on corporate landlords that Joe Biden was forced to adopt out of desperation in July — despite its massive popularity with voters, we can definitively now say, is off the table for the Harris campaign.

Meanwhile, Walz wasn’t the only one showing off his communication skills. Arguably the most notable thing about the debate was that Vance’s performance was a tacit signal of some self-awareness within the Trump campaign that the positions they’re running on are deeply unpopular and alienating to many people and have turned into a major political liability.

As a result, Vance went out of his way to pretend the campaign’s policy positions were not what they were, and to generally smooth down the extreme and off-putting nature of Trumpism and to repackage it into something reasonable. He boasted that Trump had “salvaged Obamacare” when he “could have destroyed the program,” even though getting rid of Obamacare was exactly what Trump ran on and tried to do (and even though Vance himself had told CNN in 2017 that his attempts to do so were “the thing that may be most politically damaging” for him). He lied that he didn’t support a national abortion ban and admitted that Republicans have “got to do so much better of a job at earning the American people’s trust back on this issue.” He went out of his way to express sympathy for Walz after learning his teenage son had witnessed a shooting.

It seems like it worked. According to a CNN poll, while Vance was still in the negative favorability ratings, he had dug himself out from the deep trench of public distaste he’s been in since he became running mate and videos of him insulting childless people had filtered to the public. On the other hand, the already well-liked Walz also grew his formidable favorability rating.

Walz showed last night that he has the rhetorical skills to overcome his running mate’s significant deficiencies. He could be a major political figure in the years ahead and serve as a model for progressives who have so often struggled to communicate what should be popular, appealing ideas to people who don’t share their own social and educational backgrounds. But that rhetorical style can only go so far without an actual progressive agenda that offers people new, concrete solutions. Maybe one day we’ll get both. For now, we seem cursed with only one or the other.