All you had to do was ask, it is a Gallup poll.
http://www.gallup.com/poll/118399/more-americans-pro-life-than-pro-choice-first-time.aspx
Your anti Catholic position is well known and highly visible. At any rate, if you are making a point and appropriate information, data, or graphics, it is considered good form to attribute it.
From the page:
Survey Methods
Results are based on telephone interviews with 1,015 national adults, aged 18 and older, conducted May 7-10, 2009. For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±3 percentage points.
Gallup Poll Daily results are based on telephone interviews with 971 national adults, aged 18 and older, conducted May 12-13, 2009, as part of Gallup Poll Daily tracking. For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±3 percentage points.
Interviews are conducted with respondents on land-line telephones (for respondents with a land-line telephone) and cellular phones (for respondents who are cell-phone only).
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
One of the practical difficulties with surveys conducted with this methodology is that people like me refuse to participate. That skews the poll somewhat just on that basis.