AUSTIN - Senate leaders Tuesday predicted support for a constitutional amendment banning same-sex marriages in Texas but said senators will oppose a separate effort by the House to prohibit homosexuals from being foster parents. "The Senate's very, very united in our belief that marriage should be between a man and a woman," Lt. Gov. David Dewhurst said, one day after the House had approved the gay marriage ban 101-29. If two-thirds of the Senate approves the constitutional amendment, it will be placed on the November ballot for voters to approve or reject. Texas already has a law against same-sex marriages,...