Litmus Test

During the debate (don't get me started about how they didn't say anything new), there was a question about Supreme Court justices.

McCain was asked about whether he would ever propose a candidate who was not pro-life. McCain's response was that there was no "litmus" test. He would put forward the best person. The question was turned, the other way, to Obama where he was asked if he would propose someone pro-life. He was less forthcoming on the litmus test issue in my opinion.

Questions: Should there bit a litmus test for a Supreme Court candidate for each potential president? Even if they don't say there are litmus tests, does each candidate have a litmus test?

Talk amongst yourselves....