Priests are constantly threatened by various groups (ex: Americans United for the Separation of Church and State) and by liberal lawyers that they cannot say a word about abortion, lest they lose their tax-exempt status. We caught our own diocesan atty sending letters to every priest in Missouri in 2008 election year. He lost his job, but very few knew he was caught lying. The priests were not updated and are still discouraged from speaking out. It made no difference that prolife activists had provided written legal opinions that prove church ministers retain freedom of speech, and that the IRS admits they cannot take tax-exempt status on this basis. All that said, it is simply untrue that only 1% of Catholics agree with Church teaching. On abortion, regular church-going Catholics are decidedly pro-life, despite the silence from the pulpit. This one individual pollster is not to be trusted.
Polls should never be trusted. They exist to shape public opinion, not to measure public opinion.