The WaPo offers "Brown's Turf Wars Sapped FEMA's Strength" says that the new DHS under Tom Ridge trimmed FEMA's budget, making it a shadow of its former self. FEMA head Michael Brown was a turf warrior who tried to use his White House connections to undercut the DHS, but they didn't support him:
In many ways, Brown is a cautionary tale of what can happen to Washington officials who make mistakes in the public eye after making enemies behind the scenes. Brown spent two years trying to use his contacts with White House officials to undercut DHS, but the White House rarely backed him, and DHS leaders responded by shifting FEMA's responsibilities and resources to more cooperative agencies.
Ridge stripped FEMA's power over billions of dollars worth of preparedness grants as well as the creation of a national disaster response plan. Most of the agency's top staff quit. And after he arrived at DHS in February, Chertoff decided to take away the rest of FEMA's preparedness duties.
The rest of it goes into rather disgusting bureaucratic soap opera. For instance:
"[Brown] fought being part of DHS from Day One," another top DHS official recalled.
Brown got his way on the name; Ridge and his brand-conscious aides had to admit that "FEMA" sounded better than "EP&R." But when Brown sent a memo urging Ridge to defy Congress and move the ODP into FEMA, Ridge refused.