AUSTIN, Texas -- Opponents of a proposed constitutional amendment to ban same-sex marriages in Texas have a message for you: The proposition could mean trouble for marriage between a man and woman. With telephone calls, e-mails and Internet postings, gay rights activists and others opposed to Proposition 2 are spreading that idea as part of their longshot battle to derail the measure in Tuesday's election. The tactic has supporters of the same-sex marriage ban crying foul. It has opponents boasting that they may have a chance at defeating the measure _ in Texas, of all places, the conservative home state...