Nationwide, about 20 percent of debt issued by states and local governments is sold through competitive bids. Issuers post public notices asking banks to make proposals and award the debt to the bidder offering the lowest interest cost. The other 80 percent are done through negotiated underwriting, where municipalities select a bank to price and sell the bonds.

By "negotiated underwriting," what Bloomberg means is, "local governments just hand the bid over to the bank that tosses enough combined hard and soft money at the right politicians."