Nearly three decades before he was elected President of the United States, Donald Trump was looking to build the tallest building in the world.

The plan called for a huge development on Manhattan’s Upper West Side, a towering 150-story commercial and residential project that would serve as the relocated home of NBC and tentatively be dubbed Trump City. But Trump was facing stiff resistance from community activists in the area. He wanted to marshal some data showing that everyday New Yorkers supported the project. So Trump’s company turned to a group of Democratic pollsters to conduct a survey.

The work done by the firm Penn & Schoen Associates didn’t help get Trump’s project built. But it did provide the first known link between Trump and one of the firm’s namesakes, Mark Penn, who has emerged in the last year as one of the president’s most outspoken defenders.

Penn’s columns in The Hill routinely attack the president’s political and legal adversaries. In his most recent column, published last Monday, Penn went after federal prosecutors in New York and Washington who have targeted the president and his associates.

But neither that column nor any other he’s written has revealed Penn’s past business ties to Trump. Nor has that biographical detail been mentioned in the frequent TV appearances he’s made on Fox News, in which he often attacks the president’s critics. The Hill did not return a request for comment and Fox News declined to comment.

Instead, it is Penn’s time working on behalf of President Bill Clinton during the Ken Starr investigations that is offered as proof that he brings not only an unbiased take on the current political debates, but the experience of someone who worked on the other side of the ledger.

The disclosure on his columns in The Hill, where he has published numerous pieces going after Special Counsel Robert Mueller, notes that “He served as pollster and adviser to President Clinton from 1995 to 2000, including during Clinton’s impeachment.” A Politico Magazine profile noted that Penn was “a member of a small club of Democrats in Washington shaped by Whitewater and the independent counsel investigation it spawned.” A June 2018 Wall Street Journal column that focused on Penn’s outspoken criticism of the federal investigation into Russian election meddling, was headlined, “A Democrat Dissents on the Mueller Probe.” In an Aug. 24 Fox Business interview, host Maria Bartiromo called Penn a “straight shooter” who “used to work for the Clintons.”

In an email statement to The Daily Beast, Penn said that there is a reason his past relationship with Trump has not been revealed in his various media appearances. It’s because it wasn’t really a relationship at all.

“Thirty years ago, [my partner] Doug Schoen brought in Trump and the Trump organization as a minor client to a firm neither of us has been associated with for nearly a decade. I never met his then client, Donald Trump, and, as I recall, Schoen had trouble collecting payment for his work, and had to settle largely for shuttle tickets that then became worthless,” Penn said. “Resurfacing this old news is a off-base attempt to find some irrelevant link from 30 years ago to work I didn’t do for a firm I’m no longer with, and that is not in any way related to my positions against independent counsels or as a moderate Democrat that have been consistent for over 40 years.”

“If you have to go back some 30 years to try to find some link, that’s because there is none,” he added. “I have no relationship with Donald Trump nor the Trump Organization.”

Penn & Schoen’s history with Trump does extend beyond the brief consideration of the world’s largest building. According to Gwenda Blair’s book, Donald Trump: The Candidate, Trump had the firm, which is no longer in existence, conduct polling for him as he contemplated making a run for the presidency in 1988. Blair wrote that the firm found Trump with a 75 percent name recognition among likely Republican voters. Reached for comment, Blair said she didn’t have access to the survey. But a former member of the Penn & Schoen team confirmed it was done.

After that presidential flirtation in ‘88 ended, Penn & Schoen did work on an advertising campaign that Trump put together to launch the “Trump Shuttle” airline in the early 1990s. The venture ended in bankruptcy after several years, and the former firm member said that the firm’s work for Trump ended there.

While Penn said the Trump Organization was a “minor client,” the relationship was significant enough that it was touted in promotional materials for potential clients. A 1997 story in The Washington Post noted that a Penn & Schoen prospectus boasted of the firm’s work on behalf of the Trump Organization alongside Fortune 500 companies such as Procter & Gamble and Citibank.

The Trump Organization did not return a request for comment.

When the Clinton administration ended, Trump went on to become a reality TV star and Penn stayed in politics, helping guide Hillary Clinton’s 2000 senatorial campaign, before working with a host of corporate and political clients and then taking the helm of Clinton’s 2008 presidential run. After that ill-fated campaign, Penn would do the occasional media appearance. And in April of 2011, as Trump was earning his reputation as the country’s primary skeptic of Barack Obama’s birthplace, he flatly predicted that it would be a political killer.

Will Trump ever be president of the United States, MSNBC’s Chris Matthews asked him.

“No,” Penn replied.

Trump, of course, proved him and many others wrong. And as he settled into office, Penn became one of his defenders. In an Aug. 4 appearance on Fox News, Penn called Mueller’s investigation into Russian collusion “a national waste of time.” In other appearances, he has declared that his own experience going through impeachment with Bill Clinton informed his position that the Mueller probe is wasteful and misguided.

“I’ve seen in 1998, I spent a year fighting this thing with Ken Starr and I think this thing is just plain wrong and it has got to be ended and stopped,” he told Fox News in May 2018.

Trump, for his part, has been a fan of his punditry. Less than two weeks after that May Fox News appearance, the president directly quoted Penn in a tweet aimed at undermining Mueller.

With reporting by Max Tani and Adam Rawnsley