Well yeah, as long as you ignore his plan to "Make America Great Again" which is a very conservative sentiment and presume that undoing progressive change is actually progressive, then yeah, toss that dictionary into the shredder and Trump is a "progressive".
Well some here appear to believe that America was it its most progressive at some unspecified date in the 1960s and has moved rightward since then. So perhaps Trump was the leftist you wanted all along.
I'm curious, do you really want this explained, though it is complicated? It can be, but I fear wasting my time. But here is a brief synopsis.
1) Civil Rights Act is passed and Nixon/GOP enact the Southern Strategy, an attempt to court the racist Southern Democrats into their party via racism. While the shitstorm in America that currently exists and is leading us to oblivion can be dated back to the Civil War (or even the Louisiana Purchase), it is the Southern Strategy that is key here. It was the GOP's "Making Blacks Niggers Again" movement.
2) It slowly rolled out and then come the 1980s, the Rush Limbaugh/AM Radio movement begins along side the Reagan Admin that crushed America with debt, changes to how we deal with the mentally ill, appointment of far-right wingers to SCOTUS and abolition of the Fairness Doctrine, which allow the likes of Limbaugh to breed over the radio waves. Reagan appointed Scalia and Rehnquist. It should be noted O'Connor and Kennedy were very conservative, except when it came to Civil Rights, and they almost always sided in cases that led to expanding the access of rights. For Republican replacements on SCOTUS, Roberts is the closest to either of these, but he isn't very close.
3) Newt Gingrich and the Contract for America. The GOP at this point has decided, it is party first, we must destroy the Democrats. Obstruction of Clinton was unprecedented. Alongside the flourishing of AM Radio with Limbaugh and company becoming more and more partisan, the GOP aimed at destroying Clinton instead of governing. This adversarial relationship was cited by the 9/11 Commission as one reason that Clinton was not able to address the threat of bin Laden.
4) AM Radio gains a friend in cable Fox News, which is going to explode in popularity, after an attempt to televise Limbaugh didn't work. The 2000 Election came and was a fucking nightmare. The George W. Cheney administration hit hard to the right, used 9/11 as a pretense to ignore better judgment and invaded/occupied Iraq. People that dared to question this had their patriotism questioned. This was a newish thing that we hadn't seen in decades in this country. W appoints radical Alito to the bench, who thinks that the GOP has a Unitary Executive power in the Constitution and Roberts, a guy who is trying to look not crazy partisan, but is very partisan.
5) Obama runs for office, racism abounds, obstruction of his Administration is off the charts, even as he tries to steer America in the Great Recession, which he walks right into. The Tea Party is born. The Southern Strategy has blossomed. Fox News organizes astroturfed protests over the election of Obama, not questioning the legitimacy of the election, but just protesting he won. Obama and the Dems manage to pass weak healthcare reform bill which is vilified successfully by the GOP as well as the GOP somehow blaming the Dems in state level power for the Great Recession...
6) ...and the 2010 bloodbath is the next stepping stone in the death of our democracy. The GOP was insanely margins in the election, which gave them control of everything, most importantly state legislatures, which gerrymandered the fuck out of the Federal and State Legislature districts. States like Ohio don't even need to hold elections anymore. This has led to solidly red control over states that aren't solidly red, but very much purple. The GOP are becoming bullet proof, as evidenced by McConnell stealing a SCOTUS seat appointment.
7) Fucking Trump. Solidifies radical SCOTUS with Barrett, Kavanaugh, and Gorsuch. And in the end, incites a riot that requires Congress to be evacuated in an attempt to
actually steal the election. And he was voted the top choice by CPAC for the nomination in 2024.
So... what about the progressive stuff? Make no mistake, the progressive changes in the US were almost exclusively Court ordered. Anyone that knows anything about the United States, knows that coming upon Civil Rights either takes a hundred years or SCOTUS. Brown v Board of Education, Loving v Virginia, Lawrence v Texas (of which wasn't a 9-0 result!) were all major Civil Right victories that states did not enact through legislation, but were forced by the courts. And today, the Supreme Court is wickedly to the right of any court we've likely had, these changes are going to dissolve and judicial order is going to be put in great harm because undoing these decisions could be excruciatingly hard from a legal standard to hold onto the importance of precedence.