Grandma's House

I've been thinking about something for a while now, and am looking for input. When a person serves in their state legislature, they draw a pension upon leaving. Many of those people go on to serve on the national level. Yet while they are doing so, they still get that pension from their home state. Then when they leave Congress, they get a pension there as well. Why not pass state laws to discontinue the state pension when the national pension kicks in? It would save the states a lot of money in the long run. Any ideas?