Harley-Davidson motorcycles hold a special place in the political rhetoric of President Trump. He appreciates and embraces the cultural aesthetic that accompanies the company’s products, appearing at a biker rally in the District in May 2016 at which he declared: “Do we love the bikers? Yes. We love the bikers.” That Harley is based in Wisconsin scratched various Trump itches, as well: Wisconsin is emblematic of the president’s surprise victory, and the fact that Harley manufactures there allowed him to point to his rhetoric on manufacturing as a key reason he won.

Trump met with company executives within his first two weeks in office.

“In this administration, our allegiance will be to the American workers and to American businesses like Harley-Davidson,” he said during that meeting. “And we’re very strong. In the 1980s, and I remember this, you were victims of trading abuse, big trading abuse where they were dumping all sorts of competitors all over the place, and Ronald Reagan stepped in and he put on large tariffs, and you wouldn’t be talking about Harley-Davidson probably right now if he didn’t do that. But we’re going to help you, too, and we’re going to make it really great for business.”

Trump added tariffs, as well. The European Union retaliated, including imposing a tariff on motorcycles — so now Harley is planning to move manufacturing to Europe to avoid that retaliation.

That is not, one assumes, how Trump expected it to work.

To hear Trump tell it, though, the economy is a smashing success, perhaps one unparalleled in U.S. history and clearly a function of his leadership. Just a few weeks ago, he summarized the great economic news.

There are lots of ways to nitpick his claims, including that the employment numbers build on drops under President Barack Obama. What’s fascinating about the tweet, though, is that it included a mention of the stock market, once Trump’s favorite subject — until the market started to go flat.

Trump likes to use the growth in the market since Election Day 2016 as his baseline, for the simple reason that he gets to take credit for a longer period of market growth. Since Election Day, the Dow Jones industrial average has seen its third-largest first-term growth since the McKinley administration. Since inauguration, the Dow under Trump drops to fifth place.

Still, not bad. Which is why Trump kept talking about the market, over and over and over through his first year in office.

But then the market sank, and then the market stalled. Since inauguration, the Dow is up 24 percent, but it was up 35 percent since inauguration in January. The S&P 500 is off 4.1 percent since its peak in January; the Dow is off 7.6 percent.

So, Trump doesn’t really talk about the market anymore. The comment this month was a rare exception; before that, the last tweeted mention of the success of the markets came in February, when Trump tried to blame a bad day on Wall Street on good economic news. The June tweet came after a two-week run when the Dow surged from having gained 32 percent since Election Day to 38 percent. Since then, it’s fallen back to having gained 34 percent since Election Day.

This is exactly how Trump’s rhetoric works: He embraces an isolated bit of news (accurate or not) that makes the point he wants to make. If that news keeps getting better, he updates and reiterates the point. If the news gets worse for his rhetorical point, he moves on to a new bit of news or simply sticks with the old bit of news as though nothing has changed.

During 2017, Trump’s case for his success was predicated heavily on his nomination of Neil M. Gorsuch to serve on the Supreme Court and on the success of the stock market. More recently, it’s been about jobs numbers — despite his track record of disparaging those numbers under Obama — and the tax bill passed in December. (Since which point, by the way, the Dow is down slightly. The S&P is up about 2.7 percent.) Whatever the best case is at the moment is the case that Trump presents.

A willingness to cherry-pick bits of data and a disregard for consistency have served Trump well. It’s almost hopelessly optimistic in a sense, always looking to highlight the good news and play down the bad. But it’s not about optimism, of course; it’s about continually arguing for his own success and skill.

Which brings us back to Harley-Davidson.  It’s far too early to tell what’s going to happen with the company or with the tariffs that spurred its announcement Monday. But the company has been central to Trump’s rhetoric on the economy and his political appeal. Will the president acknowledge that his tariffs have had negative repercussions in some cases and then make the case for why they still make sense over the long term? Or will he simply stop talking about Harley until he has some good news to highlight?

Harley epitomized so much of how Trump wanted to present himself. Now that its utility is more mixed, Trump will choose to accent something else.

That’s how it works. Trump is a salesman who is selling his presidency like a piece of property: No bathroom? Focus on the curb appeal. Stock market no longer the winner it used to be? Bury it deeper in the brochure until the sale is closed. But always sell, sell, sell.

One thing that’s different about selling a political candidate from selling a piece of property, though, is that a real estate transaction will eventually come to an end. Trump’s got to keep up his sales pitch until 2020.