How Republican is Fort Worth itself? Did Bush carry the city proper?
It depends on the precinct. Democrats don't sweep Fort Worth city limits entirely if that's what you're asking.
I would include some helpful links, but I'm too new here to do that. The Texas Tribune ("Can Texas Republicans hold America’s reddest large urban county?") and Fort Worth Star Telegram ("2016 election: Division in a key Texas Republican stronghold?") wrote excellent articles detailing all of this.
Welcome to the forum, BTW