Click here to see the SAS code.
Click here to see the example.

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Inspired by this article & table:
http://fivethirtyeight.com/interactives/pollster-ratings/

Using the data from their link:
https://github.com/fivethirtyeight/data/blob/master/pollster-ratings/pollster-stats-full.xlsx

Using the following variables from the spreadsheet...

Name of the polling organization. This is meant to reflect the organization that contributed the most intellectual property to the methodology and execution of the poll rather than the organization that paid for or sponsored the poll.

Number of polls from the firm in the FiveThirtyEight pollster ratings database, which covers polls conducted in the final three weeks of House, Senate, gubernatorial and presidential general election campaigns since 1998, and the last three weeks of presidential primaries and caucuses since 2000.

The percentage of polls in which the polling firm correctly identified the winner of the race. If the poll indicated a tie for the lead and one of the tied candidates won, the pollster is given credit for half a win.

A pollster's historical average statistical bias toward Democratic or Republican candidates. A score of "D +1.7", for example, indicates that the pollster has historically projected a margin 1.7 percentage points more favorable to the Democratic candidate than the actual results of the races it surveyed.