This isn't 2011, when investors piled into Treasurys during the last political battle over the budget. This time, it's different according to  Matt Tucker, head of fixed-income stategy at BlackRock (BLK).

Tucker spoke to CNBC today and what he said sounded pretty scary. In fact, if you believe Tucker, the damage may already be done -- even if the U.S. avoids a technical default in the latest political round of battles.

 

Perhaps more troubling, however, is the notion that it might not take a default for yields to rise in the long term. The standoff over the debt ceiling could have done enough damage already, Tucker said.

"Even if we get through this period, and even if we don't see a downgrade or the Treasury makes it through, what does this do to the long-term role of the Treasury as the world's reserve currency and reserve investment?" he asked.

We shudder to think. The effects on the U.S. mortgage market would be dramatic if Treasurys lost their "safe haven" status.