Never play block wargames with a dentist, they have those little mirrors to peek behind the block.
I wondered if this had been changed or if I was playing the game correctly? If the Mexican player gets dealt the strategy card which sends President Santa Anna back into exile, what is keeping the Mexican player from holding on to that card from turn to turn? Is it that the Mexican player will get just one less new card and be short a play? I saw nothing on the card saying it had to be played? There is a 50-50 chance the US player will not get the card ever in the game.
Historically I estimated there was a roughly 50/50 chance that Santa An(n)a would be driven into exile during the war... this is reflected by the card, so there is no "hole" in the game--holding it repeatedly can be a costly proposition, too.