NGTM-1R, the federal government is also more distant and so less responsive to the needs of its constituents, and it is much harder to work up a grassroots movement that affects the federal government than one that affects the state governments. While state-wide scandals may not be national news, they certainly manage to become news where it matters, the state where it all happens.
And lobbying the federal government is only harder if you aren't a massive organization with lots of money to spend on gifts for Congressmen. It is harder for Average Joe to lobby the federal government, not so much for the multi-state conglomerate Gizmos Amalgamated, Inc.