Akin spokesman labels McCaskill "Bullshitsu"

On Saturday, Missouri Republican Rep. and U.S. Senate candidate Todd Akin compared his opponent, Sen. Claire McCaskill, to a dog, saying she goes to Washington to "fetch" big government and dump it on Missouri voters.

The comparison was not well-received.

But if you assumed Akin would walk back the comment, especially in light of his growing roster of controversial statements, you were wrong.

On Monday, Akin spokesman Rick Tyler doubled down on the comparison, writing on Twitter, "If Claire McCaskill were a dog, she'd be a 'Bullshitsu'."

McCaskill's campaign immediately seized upon the message in a fundraising email sent Monday. "I'm not shocked. I'm not even upset that he compared Claire to a dog," insisted campaign manager Adrianne Marsh. "At this point, I really don't expect anything more or less from Todd Akin."

Since he secured the Republican nomination for U.S. Senate in Missouri, Akin has shuttled his campaign from one verbal faux pas to the next. He came under fire in August for stating that women who were victims of what he called "legitimate rape" could not become pregnant. A month later, after his first debate against McCaskill, Akin took issue with his opponent's aggressive posture in the debate, saying she was much more "ladylike" in her 2006 campaign.

McCaskill currently leads Akin by five points according to a RealClearPolitics average of polls, an advantage driven largely by the incumbent's strong support among women voters.