So the debt limit debate has come to this: John McCain, who you may recall was the GOP’s 2008 standard bearer, is now openly accusing conservatives of actively misleading America with their completely unrealistic demands, which he labeled “deceiving” and “bizarro.”

In a seminal moment in this debate, here’s some video of McCain on the Senate floor today, unleashing an angry tirade at conservatives who are still holding out for a balanced budget amendment as part of any compromise on the debt ceiling. McCain accused them of “deceiving” America into believing such a thing can pass the Senate:

There are Republicans in both the House and Senate who are still pushing for another vote on the balanced budget amendment, even though “cut cap and balance,” which contains such an amendment, has already failed in the Senate. Tea Party GOP senators such as Jim DeMint and Rand Paul are calling on colleagues to reject John Boehner’s proposal for a two-tiered debt-ceiling increase and are instead demanding another vote on “cut cap and balance.” Meanwhile, House conservatives such as Mike Pence are also urging another vote on a modified version of a balanced budget amendment.

To such conservatives, McCain offered a simple answer: You’re in fantasy-land, and you’re doing your constituents a disservice by perpetuating the falsehood that such a thing can ever happen.

“What is really amazing about this is that some members are believing that we can pass a balanced-budget amendment to the Constitution in this body with its present representation — and that is foolish,” McCain said angrily. “That is worse than foolish. That is deceiving many of our constituents.” McCain went on to rip the idea as “bizarro.”

Tellingly, McCain cited today’s Wall Street Journal editoral excoriating conservative opponents of the Boehner plan as out of touch with reality for thinking they can do better. McCain’s angry tirade on the Senate floor today perfectly captures the rising frustration, anger and panic of more responsible Republicans and GOP establishment figures as they come to terms with the true depths of the delusion that is now afflicting some on the right — and the danger it is now posing to our economy and country.

UPDATE: Interestingly, a source close to McCain is now clarifying to Chris Cillizza that McCain wasn’t actually attacking the Tea Party in general — he was just indicting the political process overall. More from Cillizza analyzing the meaning of McCain’s eruption right here.

More on the debt standoff:

BlogPost: More from the McCain transcript

Krauthammer: Why the Boehner plan must pass

Milbank: Boehner’s speakership crumbles

Robinson: The right is still winning

Samuelson: Retiree programs sabotage U.S’s future