Nevertheless, Hitler would never have been in position to effect a backroom deal if his party had not received 37 percent of the vote. As to your contention that Hitler himself received no votes, true enought. Neither did Tony Blair, at least not for the position of Prime Minister. He was appointed to position by the Queen because his party got a majority of seats in Parliment. England has a two party system so they don't have to deal with the problems of no party receiving a majority of the votes.
I wouldn't call the fact that the Nazis did not receive a majority of the votes as a ringing majority for democracy in Weimar. The communists and other extreme right wing nationalist parties also received votes and seats in the Reichstag.
