More importantly, this has absolutely nothing to do with equal marriage. They are trying to suggest that, if Maryland voters approve marriage equality then those who don't think that gays should be allowed to marry are in some form of peril.
Over the last four years
The ad goes on to suggest that voters are being misled by equality advocates who claim that religious liberty is protected. It's nonsense. The ballot language mirrors the legislation that is up for voter approval:
Establishes that Maryland’s civil marriage laws allow gay and lesbian couples to obtain a civil marriage license, provided they are not otherwise prohibited from marrying; protects clergy from having to perform any particular marriage ceremony in violation of their religious beliefs; affirms that each religious faith has exclusive control over its own theological doctrine regarding who may marry within that faith; and provides that religious organizations and certain related entities are not required to provide goods, services, or benefits to an individual related to the celebration or promotion of marriage in violation of their religious beliefs.Oh, and by the way, the university, and Dr. McCaskill claim that Schubert is using material owned by the university without their permission. Schubert has made a ridiculous "fair use" assertion and refused to remove the ad.