When news first broke that Herman Cain had been accused of sexual harassment, the Republican presidential candidate first blamed the media. Then he blamed liberals. Soon after, he shifted the blame to unnamed racists. Then his campaign blamed GOP rival Rick Perry.

Yesterday, the strange candidate found someone new to blame: the “Democrat machine.”

Herman Cain, the embattled Republican candidate for president, convened a nationally televised news conference Tuesday in which he insisted that he is innocent of all sexual harassment accusations, even as another woman put her name to allegations that he had approached her inappropriately.

Mr. Cain blamed the ballooning scandal on a “Democrat machine” and, anticipating calls to end his presidential run, he declared that “ain’t going to happen because I’m doing this for the American people and for the children and the grandchildren. And I will not be deterred by false, anonymous, incorrect accusations.”

Let’s note a few relevant angles here.

First, Cain’s conspiracy theory isn’t even grammatically right. I think he meant to blame the “Democratic machine.”

Second, asked for proof that Democrats had anything to do with this, Cain could offer nothing.

Third, Cain may not understand this, but I’ll let him in on a little secret: Democrats have no interest in tearing down his candidacy because they’d love it if he won the nomination. The made-up theory isn’t even plausible.

Cain’s conspiracy theory, in other words, could use a little work.

In related news, Cain insists he’d never seen Sharon Bialek before her Monday press conference, but that appears to be untrue. Cain’s campaign manager told Fox News that he’d “confirmed” that one of the candidate’s accusers works for Politico, and that wasn’t true, either.

At what point are we justified in simply labeling Cain’s entire campaign a farce?

Also note, some — and perhaps, all — of the women who’ve accused Cain of sexual harassment are preparing to hold a joint news conference of their own, according to the women’s attorneys.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.