I'd rather have postal voting along with an investment into education and enforcement of the secret ballot rights of citizens then have a polling place open for a single day with a six hour line - then again there's a lot of things the US government could do to improve the voting process, they just choose not to. Bear in mind that one party in the US doesn't like democracy and voter accessibility[1] - and please do recall Trump's specific, straight from the horse's ass, quote here:

> They had things, levels of voting that if you’d ever agreed to it, you’d never have a Republican elected in this country again.

1. https://www.theguardian.com/us-news/2020/mar/30/trump-republ...

People have cell phones in their pockets 24/7. Someone could demand photographic proof of your ballot regardless of mail in or voting booth. Sure you could doctor the photo, but you can doctor paper too. Neither are such common skill sets that there's a real difference between mail in and a booth.

So have both.