A top bond rating agency warned that a Supreme Court decision declaring New York City’s government unconstitutional could damage the city’s credit rating and ability to borrow funds. The high court ruled that the city’s powerful Board of Estimate violates the principle of 1 person, 1 vote, and ordered the city to devise a new form of government. The ruling, coming as politicians begin their campaigns in earnest for the November elections, filled City Hall with uncertainty and sent lawmakers scrambling for ways to comply with the ruling. Moody’s Investors Service, which rates credit worthiness for investors, expressed concern over New York’s fiscal stability in light of the ruling. Currently, the city has an “A” credit rating from Moody’s, which uses “AAA” as its highest rating.