May 29, 2006 -- TOP backers of former Massachusetts Gov. William Weld's bid for the Republican nomination for governor are increasingly pessimistic about his chances of defeating John Faso, The Post has learned. One prominent Weld backer conceded yesterday that the once-front-running candidate has yet to line up the 51 percent of the vote he'll need to emerge from this week's GOP convention as the party's official choice for governor.