Way too low, but then I remembered that he other 31% is people who have no opinion of Ryan, not necessarily people who have never heard of him. Same with Joe Biden having only 86% name rec...I'd be shocked if 14% of Americans don't know who Joe Biden is.
I wouldn't:
http://gawker.com/5783852/nearly-one-third-of-americans-dont-know-who-the-vice-president-isSimilarly, I don't know why people would be surprised about low numbers for Jindal, Warren, etc. Why would an average person who doesn't follow politics closely know who these people are?