FEMA says provision in appropriations act does not roll back flood insurance rate hikes.
Federal court may consider staying some of the rate hikes, research attorney says.
Mississippi-filed lawsuit now seen as last chance to stop January rate hikes.
R Street Institute pundit says NFIP reforms were too modest.
"We have a working coast, not second or vacation homes," state insurance commissioner says.
Write Your Own insurers pen strong message to Congress on keeping rate change law intact.
Mississippi lacks standing to enjoin, agency says. Massachusetts AG cites "bureaucratic ostrich headedness."
Legislation would delay flood insurance premium increases for up to four years.
Trade group cites "unacceptable financial burden" while reinsurers cast wary eye at blanket subsidies.
Measures would delay increases by perhaps four years if they gain passage.