Ok everyone stop fantasizing about carving up my state, having lived in both Dallas and currently Austin, the most conservative and liberal alike consider themselves Texans one in the same.
The answer is either both or something by itself.
And Dallas is conservative, hands down, if you live there you know that, the inner city areas my vote close to the democratic norm, but Dallas is thoroughly DOMINATED by its suburbs, more than any other city I've ever seen.
The key question here to ask is whether you are talking about the City of Dallas, Dallas County or the DFW Metroplex - because they all deserve different answers.
Democrat politics is smothered by the DFW Airport suburbs.