I found out why Walker won.
1) A lot of independents consider Walker as best option because they don't think Barrett will going be well when become a governor. They don't see situation with unions as biggest priority. They want good leadership at overall.
2) There are people don't like recall election so they sticking to vote for Walker to keep him in office until 2014, no matters if they disagree with Walker policies.
3) 17% of current Obama supporters voted for Walker for varies reason, probably not satisfy with Barrett's performance on campaign and don't think that he could handle the government job with different parties in state legislative.
4) Walker's campaign is well funded and he got a lot of support from businesses, especially Koch Brothers so he is pretty ready to survive the recall. Barrett's campaign is just very last minute, limited funded and spotty. There are a lot of wealthy liberal donors aren't going throw their money on Barrett because recall will be waste of time.
Now, Barrett lost at twice - 2010 and 2012 so he isn't going to run again in 2014. Independent voters need democrat candidate that has better critical thinking, better leadership, ability to know to handle if state legislative is controlled by different parties and better quantitative reasoning.