No, actually it does not promote voting twice unless you have the comprehension of a third grader (which is the reading levels most news outlets are written at).
He has stated for months that mail in votes get lost and not counted. The liberals claimed this would never happen. He said directly that "these people are playing dirty politics" and you have to make sure your vote gets counted.
He then CLEARLY explains that if your mail in vote is counted and you show up to vote and the system actually works, your second vote won't be counted because it will show that you already voted. Which isn't skewing any results, it is preventing people from being disenfranchised. Wait, there is that word, disenfranchised. Aren't the liberals all about avoiding disenfranchisement?
What is REALLY telling is the liberal response to this. I mean, they claimed up and down that mail om votes were basically immune to fraud and double voting, etc. Then when this happens and we catch 1000 votes, they are suddenly worried? Why? Isn't this proof they were right? No, they know they were lying and they just want to spin it now. You do realize, that the liberals have a history if voter fraud, right? Look at the Kennedy election and all the mafia controlled districts. They know how to skew an election, they don't like that they got their way and now the other side is exploiting it.
To believe that Obama wasn't implying that illegal aliens vote, and to not call him out for it is fine. But why are you not choosing to give the same type of interpretation to Trump?