The president spent much of his time at a tax event talking about other topics, from illegal voting to undocumented immigrants. (washingtonpost.com)
This isn't proof that there is any (or many) illegal voting going on - but it's also NOT a proof that there isn't. (politics.stackexchange.com)
There's absolutely no evidence at all showing that there was widespread illegal voting in the 2016 election, despite Trump's insistence that were was. (fortune.com)