>> well, jenny thomas has gotten what some criticism as has clarence thomas in the past because she wast the obama care, making money trying to make -- repeal the law. and then her husband votes on it. she ran a group that benefitted from the citizens united decision. so she could have made tens if not hundreds of thousands of dollars off that decision. repealing voting rights, abortion, gay marriage. >> and she is on this group that is actively strategizing against it. that's not a conflict, david? >> and some of these groups actually involved may be bringing cases to the court, doing friends of the court briefs. it's very, very close. i mean, for there to be an official -- an official conflict, this is really sort of walking the line. i will tell you one thing that most americans don't realize. there is a code of conduct, an ethical -- an ethics code for everyone in the federal judiciary, except supreme court justices. they don't apply these rules to themselves. but congresswoman louis slata later this week is going to introduce a bill that will make this code of conduct apply to supr

now jenny thomas clarence thomas' wife now consults for non-profits and how they can deploy money politicallyn: why was he able to give an opinion in the obamacare verdict? but a lot of folks know that scott walker was able to outspend his recall opponent 8-1. they don't know how invasive that money was other than tv ads. where did the cash go? >> some of the cash went--there was a loophole in wisconsin law that allowed walk for raise direct contributions an unlimited number for a certain amount of time. but the money being spent from outside by organizations like the americans for prosperity which is a non-profit organization that is essentially the political arm of koch industries and the koch political empire, that's one way that that money was deployed. they spent $10 million in wisconsin organizing rallies running campaign ads changing the messaging around scott walker's so call reforms which were taxed organized labor. >> we don't know how much he spent because this is another consequence of citizens united. these groups can filter their money and we won't know where it will come from.

>host: thomas henriksen is the author of "america and the rogue states" booktv is on location at stanford university. >>host: booktv from sid third university continues know we're joined by jennymartinez whose book "the slave trade and the origins of international human rights law" is our next topic. professor, when did the u.s. slave trade star in how did this start? >> u.s. was involved in the slave trade from the moment that we began as a colony of britain's and one of the interesting things of u.s. history is in the constitutional convention there was a compromise for the states that had slaves