Well, picture this: the inner city precincts -- where there are fewer than necessary voting booths, anyway, if you believe these people. Picture a few poor voters who want to vote Republican. Do they DARE do so and get caught being handed a receipt that somehow makes it evident that they voted against their's meal-ticket representatives? Do they dare come forward if a race is contested to say "I voted Republican"?
Now this sounds blatently racist, but I say this for a point: and it really doesn't matter what neighborhood, race, or ethnicity is involved here. If you are voting with a minority opinion in any election, and your ballot fails to withhold the sanctity and secrecy of your vote, then intimidation is very possible. And that is regardless of who you are.
The principle of a receipt is good; but I think the application of this is a risky scheme. Of course, I always have to be suspicious if the Democrats are proposing anything.
Only if it shows that you voted. Not if it shows how you voted, as you note above. Here's another reason why the dimbulbs might want such receipts, though: vote-buying. Figure it this way: The only way a ward heeler is going to put out good money for votes is if he can guarantee that the votes he buys are actually cast. Now, he could go into the booth with the voters and look over their shoulders -- which is why that is illegal (not that it stops the determined ones.) But with printed receipts, all the difficulties vanish away. Just bring your receipt to "Mad Mikey", showing the proper candidate has been selected, and collect your lunch money. Bring in a dozen at once, whether you voted them yourself or are brokering for your street, and get even more!
There's a reason ballots are supposed to be secret.