Ah, Jo Miller does the hard work for me. I was going to try to piece this together using census data. Federal welfare distribution by state, red vs. blue. Similar analysis by Kevin Brennan. Distribution over time, and an explanation.

As noted, it would be interesting to further break this down. Were the net welfare recipients evenly distributed, or did aid go to urban (generally blue) districts in otherwise rural (generally red) states? More in-depth questions like this.