Dems in Congress have no clue about the constitutional basis of their power

A reporter for CNSNews has been asking prominent congressional Democrats: Where does the Constitution authorize Congress to order Americans to buy health insurance? 
All of the proposed health care “reform” bills have this mandate, so obviously the majority think they have the power to  make the purchase of a product a “condition of lawful residence in the United States” (in the words of the Congressional Budget Office, which notes that such a move by Congress is unprecedented).
Of course, no such power is granted to Congress, but you wouldn’t know it asking congressional leaders.
House Majority Leader Steny Hoyer thinks that the health care mandate is no different from a general tax law:

Hoyer, speaking to reporters at his weekly press briefing on Tuesday, was asked by CNSNews.com where in the Constitution was Congress granted the power to mandate that a person must by a health insurance policy. Hoyer said that, in providing for the general welfare, Congress had “broad authority.”
“Well, in promoting the general welfare the Constitution obviously gives broad authority to Congress to effect that end,” Hoyer said. “The end that we’re trying to effect is to make health care affordable, so I think clearly this is within our constitutional responsibility.”
Hoyer compared a health insurance mandate to the government’s power to levy taxes, saying “we mandate other things as well, like paying taxes.”
The section of the Constitution Hoyer was referring to, Article I, Section 8, outlines the powers of Congress, including raising taxes, but not the purchasing any type of product or service. The opening paragraph of Section 8 grants Congress the power to raise taxes to, among other things, “provide for the … general welfare of the United States.”

Senate Judiciary Chairman Patrick Leahy simply asserts the authority:

CNSNews.com: "Where, in your opinion, does the Constitution give specific authority for Congress to give an individual mandate for health insurance?"
Sen. Leahy: "We have plenty of authority. Are you saying there is no authority?"
CNSNews.com: "I’m asking—"
Sen. Leahy: "Why would you say there is no authority? I mean, there’s no question there’s authority. Nobody questions that."

House Speaker Nancy Pelosi is flabbergasted that anybody would question Congress’ power to legislate as it pleases:

CNSNews.com: “Madam Speaker, where specifically does the Constitution grant Congress the authority to enact an individual health insurance mandate?”
Pelosi: “Are you serious? Are you serious?”
CNSNews.com: “Yes, yes I am.”
Pelosi then shook her head before taking a question from another reporter. Her press spokesman, Nadeam Elshami, then told CNSNews.com that asking the speaker of the House where the Constitution authorized Congress to mandated [sic] that individual Americans buy health insurance as not a "serious question."
“You can put this on the record,” said Elshami. “That is not a serious question. That is not a serious question.”

The question obviously caught Pelosi by surprise, and her answer amounted to “Who let this guy in here?” Later, her staff gathered its wits and fell back on Congress’ old friend, the omnipotent ‘Interstate Commerce Clause’:

Pelosi's press secretary later responded to written follow-up questions from CNSNews.com by emailing CNSNews.com a press release on the “Constitutionality of Health Insurance Reform,” that argues that Congress derives the authority to mandate that people purchase health insurance from its constitutional power to regulate interstate commerce.

Okay, I’m convinced.  How about you?