Maryland Gov. Martin O’Malley (D), appearing on CBS’s “Face the Nation” on Sunday, accused Rick Perry and the rest of the Republican presidential field of pandering to their party’s extremists and demonstrating “little serious thought” about what they would do if elected.

O’Malley, the chairman of the Democratic Governors Association, was asked about Perry’s assertion during a GOP debate on Saturday night that he would zero out foreign aid and have all countries, including Israel, make the case going forward for what they need.

Host Bob Schieffer said that assertion by Perry, the Texas governor, had caused quite a stir on Twitter and other social media.

“What’s happening in the course of these Republican presidential debates is a lot of sort of erratic statements, a lot of behavior that is not really in keeping with some of the longer traditions of the party of Lincoln,” O’Malley said. “So you see a real pandering to extremists, a pandering to the tea party extremes of the Republican party. And so this is another one in a long series of things that don’t really add up to a lot of practical sense.”

The appearance was the latest in a growing number of Sunday morning talk-show bookings during O’Malley’s outspoken tenure as DGA chairman. O’Malley shared a segment Sunday with Mississippi Gov. Haley Barbour (R) and Sen. Lindsay Graham (R-S.C.), both of whom largely defended Perry and the GOP field.

Barbour said the concept of zero-based budgeting, for example, is “not new or partisan.”

The three politicians were all asked to assess Perry’s recent inability in another debate to remember the third Cabinet department he would eliminate.

O’Malley said what he found “more jarring” was “how little serious thought many of these Republican candidates ... have given as to what it is they would actually do.” O’Malley said he had heard little from the candidates, for example, about plans for job creation or “investing” in the country.

The Maryland governor suggested that dynamic had allowed some candidates to get more attention than they otherwise would. He characterized support for businessman Herman Cain as “a protest vote.”