Take an equidistant segment from each state where the four corners meet (Arizona, Colorado, New Mexico, and Utah ) and create the ACT (American Capital Territory). Then return the parts of DC to Maryland and Virginia from whence they were taken.
The important thing to establish is that no one ever lives in the ACT. No residency. Only open when Comgress is in sesssion. The lawmakers pretty much live in barracks and eat in cafeterias. That way they're motivated to get stuff done and get out.
One big ole trailer park ought to do it. Locating in tornado country would be a bonus.
Turn Capitol buildings into museums. Build new city from scratch; nice view of Leavenworth Prison.