True, Republicans seem able to get away with blatant economic sabotage when a Democrat is in the White House. But Democrats, in part because they don’t have Fox News to insist that black is white and up is down, are much less able to pull this off. Luckily, Trump has solved their problem.

First things first: Why is an infrastructure push such a good idea? Partly because we have been underinvesting for years. The state of our roads, rail lines, water systems, and so on speaks for itself. Beyond that, private investment demand remains weak, leading to low government borrowing costs; investors are effectively begging the government to take some of their money and do something useful with it.

On top of these considerations, infrastructure spending is especially desirable in a depressed economy, when it puts idle resources to work in a way that promotes long-run growth. But, you may argue, the U.S. economy isn’t depressed right now. Indeed it isn’t; but it’s more fragile than many realize. When the next recession comes – and there is always a next recession – the conventional response, cutting interest rates, will almost surely be inadequate. On average, when recession strikes, the Federal Reserve cuts rates by 5 percentage points. Currently, however, rates are only half that high, so the Fed doesn’t have enough room to cut.

And when recession does strike, it will be too late to get a major infrastructure program going. Better to have it already underway.

So a big infrastructure push makes a lot of sense; it would also be good politics for Trump. Yet 2 ½ years after Trump took office, and after a series of “infrastructure weeks” that seem to come almost as often as the president’s golfing trips, nothing has happened. Why not?