It's too high risk for crypto exchange to do with that leverage rates. So I think no crypto exchange support it in this time.
Of course trading with 1:50 or even 1:100 is high risk, mostly for the traders though, but at least it gives a chance (for people who know what they are doing) to make some money in day or swing trades.
If you only have $1000, you need a really good opportunity to make some serious money, but if this $1000 controls $50.000 that's a whole other story.
Leveraged trading would probably mean that many fools would end up loosing their initial capital very quickly, but if the government is worried about these inexperienced people, they would have to shut down casinos immediately.
I think even a low leverage rate of 1:20 would be very nice for a start.