Huge tax cuts in the budget plans of Newt Gingrich and Rick Santorum would produce the kinds of trillion-dollar-plus deficits that the GOP candidates are blasting President Barack Obama for.

That's the finding by the nonpartisan Committee for a Responsible Federal Budget, a Washington-based budget watchdog group.

The study also says the more modest tax and spending plans of Mitt Romney wouldn't make a dent in deficits that are on track to average $800 billion or so a year over the coming decade under current trends and policies - and could add to them considerably.

Only Ron Paul, who calls for wrenching budget cuts that dwarf anything proposed by his three opponents, would reduce the flow of red ink. But even Paul's plan would leave in place large deficits.