Rich Americans have spent vast sums running for office before. Michael Bloomberg has already put them into the shade. Having spent $100m on television ads, Mr Bloomberg has tapped more of his own wealth than any White House contender in history. That is all within his first five weeks. At this rate he could exceed records by 20 or 30 times. They say money cannot buy elections (or love). Mr Bloomberg is putting that to the test. Can the White House be bought?

The history of wealthy Americans running for office is mixed. Meg Whitman, the former head of Hewlett-Packard, spent $140m on California’s gubernatorial race in 2010 and lost. Steve Forbes, the publishing executive, spent $69m on two quixotic presidential bids. Mr Bloomberg’s political career tells a different story. He spent a total of $261m on three winning races to be New York’s mayor — the last of which, in 2009, amounted to $174 per vote. His spending kept rising as his margin of victory shrank.

No one has spent more personal wealth on campaigns than Mr Bloomberg. The record for a single race came last year when J.B. Pritzker, the heir to the Hyatt franchise, spent $161.5m to win the Illinois governorship. Mr Bloomberg, in other words, has already spent more than twice as much of his own money as any figure in US political history. His record is three for three. A fourth would make him America’s 46th president. A rough estimate is it would cost him from $3bn to $5bn, which is less than a tenth of his wealth.