What a refreshing Massachusetts Senate debate. From the beginning, when moderator Jim Madigan (thank you WGBY and public television), announced that the questions would be from and based on what the public had sent in, there was hope. When the first question was not about Elizabeth Warren's heritage, but instead about unemployment and job creation, you knew we were in for a debate of substance.

Without that initial attack on Warren to set Brown up, he came off a little discombobulated. Brown was often scattered, incoherent, and thrown off by the time clock, resorting to mixing all his talking points on "bipartisan" and "job creators" into a mish-mash of word salad when he found himself with extra time. That was regardless of the question asked of him. He also failed in controlling the nasty, taking several cheap shots at "Professor" Warren, including blaming her salary and benefits as a Harvard professor for the spiraling costs of higher education.

This debate featured a far more Republican-sounding Brown that any of the previous debates. He railed about tax hikes, on his fealty to Grover Norquist, on the job-killing Obamacare. It was a bizarre juxtaposition to see the guy the tea party was so excited to get elected in 2010 and the "second-most bipartisan senator" fighting for the same brain. The results were bad for Brown.

That was particularly true when the question of health care reform came up, and Brown turned into Mitt Romney at last week's debate. He went into full Mediscare mode, repeatedly exhorting seniors watching to be terrified of the "three-quarters of a trillion" dollars in cuts to Medicare from Obamacare. He frantically asserted repeatedly that the 18 new taxes included in Obamacare were "going to crush Massachusetts businesses." Warren effectively called him out for using the "same playbook romney used a week ago," which was "wrong then, and is wrong now." Here was where all of Brown's careful efforts to avoid any connection whatsoever to the Republican party utterly failed.

Brown was evasive. When asked specifically about budget priorities—which two programs he would cut and which two were sacrosanct—Brown went into word salad mode again, reiterating his support for no cuts to defense and launching back into Obamacare lies about how much it would contribute to the deficit. Warren, on the other hand, was quick with a precise answer: she'd cut agricultural subsidies and find defense cuts made possible with the ending of two wars. She unequivocally said that she would not "go to Washington to cut Medicare or Social Security benefits.

As that answer went, so went most of the hour-long debate. Brown careered strangely between tea party talking points and insisting that he was the "last of a dying breed" of moderates, regardless of the question, and Warren providing coherent, thoughtful answers. She missed one big softball opportunity in not homing in on Brown's endorsement of Antonin Scalia as his model Supreme Court Justice when the question of women's rights came up. But she stayed focused on Brown's record and articulating the key element to this election, locally and nationally: the competing visions for the future; tax cuts for the wealthy versus everyone paying their fair share.

There will be a lot of fact-checking to do on this one, because when Brown wasn't uttering nonsense, he was talking about his instrumental role in the Senate for accomplishing everything from keeping low student loan interest rates to the existence of the Consumer Financial Protection Bureau to serving in Afghanistan.

This was a solid performance for an unflappable and articulate Warren, particularly in contrast to the rattled and often incoherent Brown. But one of the key questions for the next debate, and for the remainder of this campaign, is whether the hard-right turn Brown took in this debate is going to be the Brown that we see for the next month, or if the stress of the campaign and this debate forced him to slip up and show his true colors.

(If you missed the debate and would like to watch it, C-SPAN has it up already, in its entirety.)

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Scarce has one of the best moments of the debate in this diary.