Lawsuit to file Obama's DOMA decision
Experts divided as legal challenges loom
Speaker expects decision by week's end
Former House Speaker won't rule out impeachment hearings
President's stance on DOMA a likely turning point for marriage wars
Says POTUS believes law is "unnecessary and unfair"
Former GOP lawmaker decries Obama decision
Nadler also to reintroduce legislation in House
Says legal issues required the administration to stop defending law
Controversial Clinton-era law deemed unconstitutional
