Howard Dean blasts Ted Cruz

(CNN) - Former Vermont Gov. Howard Dean on Thursday described Republican Sen. Ted Cruz and others who support threatening a government shutdown in order to defund Obamacare as "irresponsible" and "petty, radical-right people."

"We can do better this, and I think the American voters are going to throw these people out," he said on CNN's "The Lead with Jake Tapper." "If they keep doing this, the impossible may become possible. We could take back the House in 2014."

In Texas this week, Cruz is holding town halls rallying supporters around the idea of urging Congress to strip money for the president's signature health care plan before voting on the next funding measure in September.

But Dean argued "people do not want to put up with this kind of stuff" and "it's about time Ted Cruz started thinking about America and not himself."

The 2004 Democratic presidential candidate also didn't rule out another White House bid. Dean stopped in Iowa this week and travels to New Hampshire next month, fueling speculation he's considering a run.

But Dean maintained Thursday he's supporting former Secretary of State Hillary Clinton, should she decide to launch a campaign.

"I really do think it's much too early to be talking about who's going to run for the president," he said. "Really and truly it's not why I'm going to Iowa and New Hampshire."

However, he didn't shoot down the idea that he could potentially enter the race. "In politics, you never say never about anything."

Dean came under criticism this month from some on the left after he wrote an editorial blasting a provision under Obamacare-the Independent Payment Advisory Board, a panel charged with keeping Medicare costs under control. It was famously dubbed a "death panel" by former Alaska Gov. Sarah Palin, pointing to a part of the bill that required Medicare to pay for some end-of-life planning counseling sessions.

But Dean, focusing on the cost-cutting responsibilities of the IPAB, argued "regulatory approaches to cost-controls have not worked in 30 years in this country." Several Senate Democrats up for re-election next year also agree with him.

Some liberals, however, were quick to point to Dean's role as an adviser to a Washington law firm that has ties to the health care industry. Defending himself, Dean said it's all too common in Washington for critics to make assumptions based on peoples' connections.

"I was a little disappointed in the left–not for criticizing my views," he said. "It's because the first thing out of their mouth is 'This is about you. You're wrong. You're taking money.' Why can't we have a debate about ideas in this country instead of what our motivations are?"

Calling it a "death panel," however, was a "ridiculous statement" by Palin, he said. "That's not what it is."

"We've got to fundamentally change the system and get rid of fee-for-service medicine," he argued.

A physician, Dean also weighed in on the renewed medical marijuana debate, following CNN's Dr. Sanjay Gupta's decision to change his mind and support marijuana for medicinal purposes.

Dean said he doesn't have a problem with decriminalizing marijuana, but when it comes to medicine, he "really doesn't like hocus pocus."

"I'm not unwilling to let people use marijuana who have failed on other kinds of treatments. I'm not. But I am unwilling to have the government bless a delivery mechanism which is nonsense. If you want to use medical marijuana, let's use the active ingredients; let's not have people inhale it."