Are Republicans Hypocritical About Cliff?
If Heritage and the others had used Keynesian arguments against the cliff, then Krugman would have a point, but they usually don't (except when it comes to military spending where many Republicans indeed use Keynesian arguments in a hypocritical way ). Instead, their main problem with the cliff consists in that it would mean an increase in marginal tax rates that is particularly dramatic when it comes to dividends, but also capital gains and compensation of workers. By contrast, Obama's so-called stimulus didn't lower marginal tax rates.
Krugman can argue that the concern about the incentive effects of higher marginal tax rates is exaggerated, but it is obvious that it is not hypocritical.