Cliff jumpers.

"A growing bloc of emboldened liberals say they’re not afraid to watch defense spending get gouged and taxes go up on every American if a budget deal doesn’t satisfy their priorities."

Here’s what these progressives fear: an agreement that keeps lower tax rates for the wealthy, hits the social safety net with unpalatable cuts and leaves Pentagon spending unscathed. In other words, they’d rather walk the country off the cliff than watch President Barack Obama cave on long-held liberal priorities.