So, what would happen if he declared Martial Law in heavily democratic states during the election?
There is a basic impracticality to it; he would have to do so early enough to stop voting, it would be reported on CNN, and voter turnout would in all likelyhood soar...against him. Or Congress would throw his ass out of office. Under those circumstances I don't think the Republican Party would back his play. So, it's suicide even if it actually gets that far. Which it may very well not.
Put simply, such an action would be blatantly wrong and certainly violate the spirit if not the letter of the oath everyone who joins up swears at some point. The military, in the august persons of the Joint Chiefs of Staff, doesn't like Bush much anyways. They may refuse to carry it out. Even assuming they do, declaring martial law requires troops...and the only practical options in most democratic states are National Guard troops already in place. Who are even more likely to refuse to carry out such orders, since they adminstratively "belong" to the state. It's happened once in US history already, over the enforcement of
Brown v. Board of Education. So at the least the troops would have to be shipped in from elsewhere, which takes time. The vote would probably go forward and be done before it could be effectively implemented, or by the time the vote would take place Bush would have been tossed from the steps of the White House. Take your pick.