It could be because they think they're THAT close to achieving their goals for our Republic.
If WE realize how important this particular election is, they probably do too. Once they get millions of illegals in and voting, it's over. Done. And they know it. All they have to do is get her elected by dragging her over the finish line with electronic voting theft in a few key districts/states (PA & OH would be my bet). Then they'll have what's-his-name as a malleable VP to install as President.
It is up to us to have such a large vote for Trump, even their dead and illegal voters will have no impact on the results.