Could a time machine be used to remove Hitler?

OK, so it sounds like a fantasy. Go back in time remove Hitler, prevent WWII and save millions. Can it be done? Should it be done?

Actually, if we did used a time machine to remove Hitler, then another person would take his place. For example, if Obama had not run for president in 2008, then Hillary would have won. If Bush had not run in 2000, then McCain would have won.

Without Hitler, Ernst Röhm leader of the brown shirts a very popular figure in Germany, would have taken power and won WWII. As they say, be careful what you wish for, because Hitler ordered Ernst Röhm executed during night of the long knives. Without Hitler he would have been successful.

Using Steven Gibbs HDR it is possible to see future events and on alternate timelines to see other pasts. A future where Germany won WWII even without Hitler would be dim and grim for the world. Ernst Röhm was no saint and he would have been a terrible dictator, if possible, even worse than Hitler.