I don't have a ready estimate of how much capping deductions for those earning more than $250,000 would raise. But you can ballpark it by looking the Tax Policy Center's estimates for capping itemized deductions at $50,000. It would raise $749 billion over 10 years, within the $800 billion that Mr Boehner has previously agreed to. That’s also more than the $429 billion yielded from returning the two top rates to their pre 2001 levels.
There is much more, so read the original.
There is no problem with the two solutions mentioned in the quote being utilized, it is not by any means only an either/or situation.
The sidebar links: here, here and here.
Complete Krugman post, here.