[ISiddiqui]

Not only will it get the other guys mad, but it'll allow your opponent an ability to counter the charges in an official manner - who exactly do you think controls the Senate (and therefore controls the manner of the trial after the House votes to impeach)?

Prosecutors don't prosecute cases they can't win as a matter of course. It's commonly said that if the feds charge you, they know they have a winning case. If you lose because you planned terribly or didn't get all the info you could, you don't have any second shot. Impeachment is similar. You get one shot - it behooves you to make sure you don't waste it.