At the end of the first page, Roger Lowenstein, the author of the piece, makes the following point:
Another problem is that, assuming Washington does have some influence, attributing it to the appropriate officeholder is next to impossible. The labor market does not correspond to neat, quadrennial cycles, and the notion that the Bush team, which took office when the economy was already cooling, precipitated a decline in the job market that began 10 weeks later is simply implausible. Governmental decisions have a long half-life. The balanced budget achieved by Clinton in 1998 owed much to the 1990 budget agreement forged by the first President Bush, who had been kicked out of office as a failure. If you want to blame the current president for a recession, argues Jeffrey Frankel, a Harvard economist, blame him for the next recession, because the Bush deficits will seriously narrow the options available to whoever is unlucky enough to be presiding then.
Any good that a politician's policies might create will not be visible, will not cross the horizon, until well after he is out of office. Ditto for an opponent looking for mud. The poitical horizon, defined by the next election when the politico is called to task, is much shorter than the economic horizon in which it can truly be judged whether said politico was effective. Sad but true.