source                            date clinton obama undecided
0                    surveyusa          may 16 - may 18 , 2008     42%   55%        1%
1                      suffolk          may 15 - may 17 , 2008     41%   45%        8%
2      american research group          may 14 - may 15 , 2008     45%   50%        5%
3    public policy polling (d)          may 10 - may 11 , 2008     39%   53%        7%
4                    surveyusa           may 9 - may 11 , 2008     43%   54%        2%
5  davis , hibbitts & midghall           may 8 - may 10 , 2008     35%   55%       10%
6            rasmussen reports                    may 1 , 2008     39%   51%       10%
7                    surveyusa      april 28 - april 30 , 2008     44%   50%        4%
8                    surveyusa        april 4 - april 6 , 2008     42%   52%        3%
9          riley research poll  january 21 - january 29 , 2008     36%   28%       13%

Table as JSON:
{"source":{"0":"surveyusa","1":"suffolk","2":"american research group","3":"public policy polling (d)","4":"surveyusa","5":"davis , hibbitts & midghall","6":"rasmussen reports","7":"surveyusa","8":"surveyusa","9":"riley research poll"},"date":{"0":"may 16 - may 18 , 2008","1":"may 15 - may 17 , 2008","2":"may 14 - may 15 , 2008","3":"may 10 - may 11 , 2008","4":"may 9 - may 11 , 2008","5":"may 8 - may 10 , 2008","6":"may 1 , 2008","7":"april 28 - april 30 , 2008","8":"april 4 - april 6 , 2008","9":"january 21 - january 29 , 2008"},"clinton":{"0":"42%","1":"41%","2":"45%","3":"39%","4":"43%","5":"35%","6":"39%","7":"44%","8":"42%","9":"36%"},"obama":{"0":"55%","1":"45%","2":"50%","3":"53%","4":"54%","5":"55%","6":"51%","7":"50%","8":"52%","9":"28%"},"undecided":{"0":"1%","1":"8%","2":"5%","3":"7%","4":"2%","5":"10%","6":"10%","7":"4%","8":"3%","9":"13%"}}