The Tea Party didn't spend the country into bankruptcy. Indeed, they've tried to STOP this nonsense.
The Tea Party didn't rob the Social Security accounts, taking the money and spending it on pet-projects, and now leaving the aged without their promised safety-net.
If you think the Tea Party is responsible for the downgrading, then you should shoot yourself in the head.
If it is true that financial markets are not concerned about the size of the debt, but about the way some in government are willing to handle the debt - then yea, the tea party bears some responsibility.