Among other things, it would automatically register eligible voters via information they provide to various government offices, such as the DMV. A number of states have take this kind of legislation up, and a few have passed it, but it would be wonderful to have this on a federal level, for all states.
It's S. 1353 in the Senate and H.R. 2876 in the House. Call your reps and ask them to support this act by co-sponsoring it.
What we're seeing right now in Washington with the AHCA is what happens when the elected officials are not sensitive to the needs of their constituents. To force them to care, we have to make it easier for those constituents to make their voices heard in the voting booth.