In relation to Trump's executive orders, both the first version and the new watered down one, it seems that two (or more) separate judges were asked to rule on its constitutionality. How can this be possible? Here are some specific questions:

• Why didn't the judge in Maryland just say that the question had already been handled by another judge at the same level in Hawaii?
• What happens if they make contradictory rulings?
• If Trump wants to appeal, does he have to appeal each ruling separately?
• Could, in theory, 50 separate federal judges have been asked to rule on exactly the same question at the same time?