It is a mystery. You do not say "X says Y" and then cite to a work in which "X says not Y". You simply do not do that:
Mark of West Coast Stat Views: Joe Scarborough and Jeffrey D. Sachs… start with the following paragraph:
Dick Cheney and Paul Krugman have declared from opposite sides of the ideological divide that deficits don’t matter, but they simply have it wrong….
As a commenter on Krugman's blog pointed out, if you click on Krugman's name in that paragraph, you'll end up at a post that starts as follows:
Right now, deficits don’t matter — a point borne out by all the evidence. But there’s a school of thought — the modern monetary theory people — who say that deficits never matter, as long as you have your own currency. I wish I could agree with that view — and it’s not a fight I especially want, since the clear and present policy danger is from the deficit peacocks of the right. But for the record, it’s just not right.
In other words, to support the claim that Krugman said deficits don't matter, Scarborough and Sachs point to Krugman saying explicitly that people who say deficits don't matter are wrong. Krugman then spends pretty much the entire post arguing that deficits will matter a great deal once we're out of the liquidity trap.