Even in his appearance on ABC, Holder makes a case that Miranda has not impeded any investigation to date:
The system has proven to be effective. …. people have been given Miranda warnings, people have continued to talk, as was the case [with Faisal Shahzad], as was the case with Abdulmutallab in Detroit.
And Holder has made even more passionate defenses of Miranda in the past, notably in Congressional testimony (see some quotes from such testimony here). Nevertheless, Holder effectively uses his Sunday show debut to say, “If it ain’t broke, but fearmongers like Joe Lieberman and Lindsey Graham want to attack it nevertheless, then hell! Let’s break it!”
But gosh. It sure is nice to see the last defender of rule of law allowed to appear on the Sunday shows!