The Supreme Court decision that changes the provisions in the Voting Rights Act adds legal risk for state and local governments.
The local government is seeking to replace LUMA Energy as the island's transmission and distribution company.
"I don't mind owning a railroad for $2.4 billion," said Assured CEO Dominic Frederico.
Northwest Nazarene University, an Idaho private Christian college, had its ratings outlook revised to positive.
Munis should do "relatively well" this month, as investors will "focus on heavy summer redemptions; tax-exempt supply should remain healthy but is unlikely to overwhelm," said Barclays strategists.
The Manhattan-based Ivy League university reached a settlement with the federal government last year. It is selling $487 million of bonds this month.
