Bentsen in a heart beat, he and John Glenn and perhaps Hugh Carey and Mario Cumo where the outstanding Democrats of their generation
Bentsen would probably pick Gore or Gephardt to be his running mate and i think the election would be really close...
Bentsen/ Gephardt (DEM) : 292
Bush/ Quayle (REP) : 246
...that said TX, LA, AR, IL, NJ and PA would have all been close between Bentsen and Bush, that said in the end i think that perhaps the Reagan effect could have thrown the election to Bush by the slimmest of margins, but it really really would be close