Hard to imagine how the Tea Party could have hurt itself more, other than actually to have caused a U S government default on paying its bills, which so many of them actually wanted to do. The Tea Party seems to me to be led by the Confederate Southern states, who seem to love "heroic lost causes", for example, Pickett's charge that lost the battle of Gettysburg, and the Civil War. I guess it makes them feel brave.
It looks to me like the Tea Party is a kind of a romanticized idealism of a lost civilization, the Confederacy, and are ever dedicated to the hope that The South Will Rise Again. Or, more to the point, they seem to be dedicated to a notion of Southern manhood. I have no idea why any of the rest of the country gets sucked into their long dead fantasies.