Former Democratic Party Chairman Howard Dean decried the resignation of Van Jones from his post as the White House green jobs czar, saying that Jones was "brought down" by critics on the right.

Dean noted that Jones was a Yale-educated lawyer and author of a best-selling book calling for an economy based on environmentally friendly jobs.

"I think it's a loss for the country," Dean said on "Fox News Sunday."

Jones's conservative critics, led by talk-show host Glenn Beck, had criticized Jones for signing a letter calling for a probe into whether President George W. Bush and other government officials had allowed the Sept. 11 terror attacks. Jones also came under fire for derogatory comments toward Republicans. One YouTube video showed him calling Bush a "crackhead."

Jones had apologized last week for some of his remarks and said that the letter he signed calling for another 9/11 investigation didn't reflect his views.

Dean said that Jones signed the letter because it was offered to him by someone "waving clipboards around," not because he believed it.

Sen. Lamar Alexander (R-Tenn.), also on "Fox News Sunday," said that the larger concern should be over the proliferation of White House czars, who wield much power but aren't subject to Senate confirmation.The more than 20 czars in the Obama administration are "an affront to the constitution," Alexander said.

"When you take all these people and make policy close to the president and the White House, you're just adding fuel to the fire to those who think Washington is taking over everything," Alexander said.