The traveling snake oil salesmen of the late 19th and early 20th centuries had their share of success for several reasons. They were effective pitchmen who sold hope in the form of miraculous cures from exotic—but ultimately ineffective—elixirs. They understood the importance of moving from town to town, knowing that the deception would eventually catch up with them if they stayed too long in one place.

Snake oil has disappeared, but con men never do. The techniques remain familiar. Some, like those behind Ponzi schemes, promise extraordinary returns while paying early investors with money from new ones. Charles Ponzi became synonymous with the scheme, and Bernie Madoff later operated one of the largest financial frauds in history. Frank Abagnale impersonated a pilot, doctor, and lawyer while passing fraudulent checks.

Donald Trump reminds me of these and other confidence men—not because the tactics are identical, but because the central strategy is familiar: selling a compelling story about himself. He rose to the highest office in the land by mastering the techniques of a political showman and confidence man on a national stage. His primary product has always been himself, and he has transformed personal charisma into political currency. Twice, he convinced a majority of Americans that he alone could solve their problems.

However, just like ineffective snake oil, there comes a point when some customers begin to question what they purchased.

Trump’s poll numbers have declined significantly. Major surveys show his overall approval rating below 40 percent, with disapproval approaching 60 percent. A Washington Post-Ipsos poll found only 33 percent approved of his handling of the economy. Newsweek reported that Trump was underwater in every major battleground state 18 months into his second term.  A CNN poll found that 73 percent of U.S. adults “say that President Donald Trump hasn’t paid enough attention to the country’s most important problems.”

The warning signs were evident in his recent speech. A president who asks for airtime to address the nation is expected to offer something meaningful. Instead, Trump’s remarks relied heavily on familiar and false claims about election fraud and repeated exaggerated assertions about vulnerabilities in the electoral system.

The reaction from fellow Republicans was also revealing. Many had little to say about the address. The New York Times reported that even Fox News’ morning program, which has traditionally been supportive of the president, gave the speech little attention.  Republicans on Capitol Hill grumbled that Trump was wasting time that should be spent on more relevant issues.  The Wall Street Journal opined that “Republicans should be campaigning on what they want to do with the two more years in power” instead of being forced to defend Trump’s disjointed monologues about elections.

Successful politicians understand that power is constantly shifting. Many Republicans remain willing to tie themselves to Trump’s boat, but they are also watching the horizon. If that boat begins to founder, some will look for another vessel.

The war with Iran continues to expand.  Gas and diesel fuel prices are increasing again.  Families remain concerned about the rising cost of goods and services. Trump and members of his family have used political positions in ways critics argue have benefited their personal interests. Meanwhile, how many Americans are really sitting around their kitchen tables re-litigating the 2020 election?

Some argue Trump is engaged in classic misdirection: create a spectacle over there so people pay less attention to what is happening right in front of them. Perhaps. But the strategy appears to be losing some of its effectiveness.

There are still plenty of believers who make their way to the front of the stage, captivated by Trump’s razzle-dazzle performances. But as the polls suggest, the crowd behind them is thinning. They have heard the promises before, and the miracle tonic they were sold is not producing the results they were promised.

The question for every huckster is the same: how long will the customers keep buying?