COVINGTON, Louisiana (Reuters) - First lady Laura Bush joined her husband in defending his nominee to the U.S. Supreme Court on Tuesday and said it was possible some critics were being sexist in their opposition to Harriet Miers. "That's possible, I think that's possible," Mrs. Bush said when asked on NBC's "Today Show" whether criticism that Miers lacked intellectual heft were sexist in nature. She said Miers' accomplishments as a lawyer were a role model to young women. ... Mrs. Bush, who had publicly supported the nomination of a woman to the high court, noted that Miers had been president...