Nearly a week has passed since the election, yet the apparent loser of one of the hottest contested races for Congress in Dallas-Fort Worth is refusing to concede defeat.Democrat Candace Valenzuela, a former Carrollton-Farmers Branch school trustee, ran a strong underdog campaign for Congressional District 24, which includes much of Northeast Tarrant County and the suburban neighborhoods between Fort Worth and north Dallas. The district was pegged as one of several former GOP strongholds that Democrats hoped to win.But, with 100% of precincts reporting, Valenzuela remains 4,489 votes behind Republican Beth Van Duyne, a former Irving mayor who was supported...