“From the Rose Garden I always promised you a crime pardon” Lynn Anderson never belted out those lyrics, but that’s apparently the tune that outgoing President Donald Trump has been singing these days, using his powers to preemptively wipe the culpability slate clean for friends, family members, those who have done him favors, accomplices like Rudy Giuliani and, oh yeah, himself.

But despite the presidential power afforded by the Constitution “to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment,” the extent of that authority has not been thoroughly tested in the courts, even after all this time, meaning the lawyers haven’t got their hands on it.

Does the chief executive actually have preemptive pardon power or, as some law professors argue till our eyes glaze over, does he need specifics of a legal violation before he has anything to pardon? And can he pardon himself?

That is untested, but his power only extends so far. It solely covers federal law. State and local codes and suits are unaffected. Any attorney worth his or her billable hours in salt can come up with a way to find that some jurisdiction, somewhere, has a law against whatever he or she would like to prosecute or sue against.

In the case of Trump and his cronies, they already are defendants or are being investigated for all manner of transgressions. Expect “political revenge” to be a constant claim of theirs as they cope with their legal struggles.

At the same time, expect Donald Trump to set up what amounts to a shadow government, relying on anti-social media to spread his grievance du jour. His showmanship will be a key to keeping him in the news.

And that presents those of us in newsbiz with a problem. Assume that President Joe Biden will be carefully tweeting pablum. Modern demagoguery techniques are not their style; they are Donald Trump’s style. As journalists, we need to decide whether to continue to pay attention to his cyber bombast after he doesn’t hold the power to annihilate

the planet. Do we care what he churns out as part of his routine?

Will his rallies become a thing of the past, remembered as a sign of the times, much like the rock shows of the Grateful Dead in the ‘70s? The Dead had their own superfans who followed the band wherever it went. They became known as Deadheads. Donald Trump has his own rabid base with those who travel near and far to cheer his every ignorant, bigoted song and dance. Will they become known as his Hateheads? The difference is that the Dead was one of the greatest rock bands ever, putting out incredible music. The Donald puts out a steady stream of lying drivel.

But both cultural phenomena have something in common, like the “Trouble ahead, trouble behind” that is a lyric in the Grateful Dead’s iconic song “Casey Jones,” and would also describe the overall legacy of Donald Trump.

Actually, it’s essential to remember that before we look to the future, we need to worry about the present. He still is president, still has the ability to inflict so much damage on our country. He will certainly leave behind millions who no longer believe in the democratic processes that define our imperfect nation, which is fertile ground for an autocrat’s takeover. Certainly Donald Trump will be waiting in the wings with his remarkable egotism.

Bob Franken is an Emmy Award-winning reporter who covered Washington for more than 20 years with CNN.