Former Pennsylvania Senator Rick Santorum has joined Minnesota Rep. Michele Bachmann in signing an anti-gay marriage pledge, The Washington Post reported.

The pledge, titled The Marriage Vow: A Declaration of Dependence Upon Marriage and Family, was introduced Thursday by the Iowa-based Christian conservative group The Family Leader. It asks 2012 candidates to “vigorously” oppose marriage equality, be faithful to their own spouse, vow to protect women and children from pornography and reject Sharia law because it is a “form of totalitarian control.” The group, influential among social conservatives, has said it will not endorse any candidate that does not sign the pledge.

The pledge ironically also asks candidates to have “Respect for the marital bonds of others.”

Footnotes to the two-page document suggest that being gay is a choice and may have a negative impact on public health.

Bachmann, who in 2004 as a Minnesota senator sponsored a constitutional amendment to ban gay marriage in the state, signed the pledge on Thursday. An aide of the candidate, Alice Stewart, told the paper that Bachmann had no qualms about signing the pledge.

Since officially entering the race, Bachmann has kept quiet about her views on gay rights.

Santorum, on the other hand, has stepped up his anti-gay rhetoric, announcing this week that he's opposed not only to marriage but also civil unions for gay couples.