Former President George W. Bush followed up his re-election with a public relations campaign in early 2005 to reform Social Security. It did not go well, and Bush’s failure — made inevitable by the mishandling of Hurricane Katrina — confirmed to Washington that Social Security was the “third rail” of politics and should never be touched.

It has lain untouched ever since, perhaps partly because Social Security is not the most pressing strain on federal finances. But it is a very serious one in the medium and long term.