From the August 4 edition of C-SPAN's Key Capitol Hill Hearings:
PRES. BARACK OBAMA: At the end of the day, it is the American people's decision. I have one vote. I have the same vote you do. I have the same vote that all of the voters who are eligible across the country have.
Of course the elections will not be rigged. What does that mean? The federal government doesn't run the election process. States, and cities, and communities all across the country, they are the ones who set up the voting systems and voting booths and if Mr. Trump is suggesting that there is a conspiracy theory that is being propagated across the country, including in places like Texas, where typically it is not Democrats who are in charge of voting booths, that is ridiculous. That does not make any sense. I don't think anybody would take that seriously.
This will be an election like every other election. I think all of us at some point in our lives played sports or just played in a school yard or sandbox. Sometimes folks, if they lose, they start complaining that they got cheated, but I’ve never heard of somebody complaining about being cheated before the game was over or before the score is even tallied. So my suggestion would be go out there and try to win the election. If Mr. Trump is up 10 or 15 points on election day and ends up losing then maybe he can raise some questions. That doesn’t seem to be the case at the moment.