“There is one scenario in which Obama has to carry only 19 states plus DC to garner 271 evs - and these are all states he carried last time.”
In the scenario I mentioned, the Republican candidate wins all of the McCain states plus IN, NC, VA, FL, OH and the Omaha CD, and Obama draws an inside straight and wins the remaining 23 states (plus DC) and ekes out a 272-266 Electoral College victory. I don’t think that Obama can win FL, so the inside straight is his best bet.
“Whomever wins 2 of the 3 following states will be elected president - FL, PA, OH”
If the Republican wins FL and OH, or FL and PA, but Obama wins the other state, Obama still has a chance of drawing the inside straight and winning (with 272 EVs if he wins PA and with a bare-minimum 270 EVs if he wins OH); remember, Bush won two of those three states (FL and OH) in 2000 and it would have all been for naught had he not carried NH by a little over 1% (the Dems made sure to steal WI, NM and OR). And if Obama carries FL, he could win despite losing not only OH and PA, but WI (or MN, or CO, or both NV and NH, or both IA and NH, or both NM and NH) instead.
Right, trade FL for OH. My point is that there are inside-straight scenarios that make his re-election possible in the low 270s - as you’ve identified.