Rupert Cornwell: Are we going to see Ronald Reagan on America's $50 bill?

Liberals are aghast. Historians of America's Civil War are beside themselves. How could anyone seek to change the image on the US $50 bill, replacing Ulysses S Grant – the Union general who accepted the surrender of Robert E Lee in 1865 – with a one-time Hollywood actor nicknamed the Gipper?

Yet that is exactly what Patrick McHenry, a Congressman from North Carolina is seeking to do. Next year marks the 100th anniversary of the birth of Ronald Reagan, and last Friday Mr McHenry formally introduced the "President Ronald Reagan $50 Bill Act", stipulating that all such banknotes printed from the start of 2011 "shall bear the likeness of President Ronald Wilson Reagan". First, however, the good congressman must overcome Americans' reluctance to change the way their money looks.

On the face of it, the change would not be unreasonable. Those depicted on a country's currency are normally its greatest citizens. Grant, who conducted a victorious campaign across the South, was one of Abraham Lincoln's most aggressive and successful commanders. But his eight years as the country's 18th president were, to put it politely, mediocre.

Less than a generation has passed since Reagan was in the White House, but historians now regularly rank Reagan among the top dozen US presidents. Yes, he remains controversial, as disliked by many Democrats as he is revered by Republicans. But you could argue he's no more controversial than Grant is in some corners of the old Confederacy even today.

But changing the faces on American coins and banknotes is not that simple. For a president, the only quick way of being elevated to the currency is to die in office. Franklin Roosevelt was gracing the dime, worth 10 cents, in 1946, just a year after his death. JFK's ascent was even faster; the Kennedy half-dollar was designed within three months of his assassination in 1963.

Reagan, on the other hand, like Grant, had left the White House long before he died. Grant's supporters had to wait until 1913, 28 years after his death, before he popped up on the $50 bill and, on this timetable, Reagan should not appear on a banknote until at least 2032. Iin terms of being officially remembered, he's not doing badly already. An aircraft carrier, several highways and a gigantic federal building in Washington have been named after him – not to mention the capital's airport. True believers have even lobbied for a spot for Ronnie on Mount Rushmore. That, though, will never happen – if only because the local granite reportedly can't handle the strain of a fifth Presidential face, of whatever party, being carved into it.

But there's a second, perhaps deeper reason for doubt. In the US you tinker with the currency at your peril. When it comes to the appearance of their money, Americans are the most conservative people on earth. Today's bills have been exactly the same size since 1929. The highest denomination ones, such as the $5,000 "Portrait of [President James] Madison", familiar to devotees of Raymond Chandler's The Long Goodbye, have long since been withdrawn from circulation. But apart from some security improvements, larger numbers and a dash of colour, those that remain – from $1 to $100 – are little changed. And that goes for the faces that adorn them: Washington on the $1 bill, Lincoln on the $5, and, of course, Grant on the $50. Is Ronald Reagan now going to upset this unrivalled paper money stability?

Now and then, well-meaning souls propose abolishing the $1 bill and replacing it with a coin. Not only would this bring the US into line with other rich countries such as the euro bloc or Britain, they argue, whose smallest denomination notes are worth $7 or more. It would also spare forests of trees as well as $500m a year in government spending. But Americans will have none of it. Dollar coins, mainly issued as change by automatic vending machines, just don't seem real.

And the same goes for any attempt to meddle with the coinage. Be it war, inflation or political fiat – nothing can disturb the eternal order of penny, nickel, dime and quarter. Kennedy half-dollars are now solely for collectors. As for the copper and zinc penny, the cost of making one is almost double its face value of one cent. But save taxpayers $50m a year by getting rid of it? Perish the thought. Like old soldiers, American coins never die. They just fade away.

This isn't the first time Republican lawmakers have tried to put their hero on a banknote. But, once again, the chances must be next to zero of a $50 bill with Ronald Reagan grinning from its obverse – even if his Republican party regains control of Capitol Hill this autumn. Let the country print dollars like never before to cover its deficits. Just don't change the way those dollars look.