Hitler was not elected to power, he was appointed Chancellor. The elections that followed brought the Nazi Party to power and were highly questionable.
He was appointed to power because the Nazi party gained a large number of seats in the Reichstag.
At the end of July the Nazi party gained almost 14,000,000 votes securing 230 seats in the Reichstag. Energised by the incredible results Hitler asked to be made Chancellor. Papen offered the position of Vice Chancellor but Hitler refused.
.... The Nazi party lost 34 seats in the November 1932 election but remained the Reichstag's largest party.... In November Papen left office and two months later secretly told Hitler that he still held considerable sway with Hindenburg and that he would make Hitler chancellor as long as he could be the vice chancellor. On 30 January Adolf Hitler was appointed chancellor of a coalition government comprised of the NSDAP-DNVP-Centre Party....Hitler soon moved to consolidate absolute power,
http://en.wikipedia.org/wiki/Nazi_Accession_Question
So, the point was that the Nazi Party, under the leadership of Hilter, came to power legitimately, or at least under the cloak of legitimacy, but once in power, took total control.
So, a Democracy is only as strong as the peoples commitment to it, it cannot protect freedom if the people are willing to give their freedoms up for security.