Stretching

Charles Lane asks whether "nationalizing GM" was constitutional, and sums up his own answer this way:

In other words, sometimes the president can get away with stretching his authority because Congress would rather not be held accountable for formally defining it.

The whole "checks and balances" thing only limits the presidency when the other branches wake up and say "What the...?"

They all swear to uphold it
but many of them fold it
and stick it in a drawer
and read it nevermore.