Exactly what he said he meant [0]:

> It’s true, because we have to get the vote out. Christians are not known as a big voting group, they don’t vote. And I’m explaining that to them. You never vote. This time, vote. I’ll straighten out the country, you won’t have to vote any more, I won’t need your vote any more, you can go back to not voting.

Basically "the country is screwed up right now because ${reasons}, if you get out and vote I'll fix it for you for good and you can go back to not voting again". It's more or less the same line that politicians say every election to try to motivate the less-likely-voters in their base, just said in Trump's classic meandering way and with explicit permission to vote only this once if you want.

[0] https://www.theguardian.com/us-news/article/2024/jul/30/dona...

I'm a "supporter" and I know exactly what he means. Means he'll fix all the voting shenanigans so that illegals can't vote and so that democrats can't "rig" and stack the election like last time. See? Not so much a hateful whistle as it is understanding your supporters, what's important to them, and appealing to that with your own words.