Germany and German society today are much different than that of 1930s and 40s Germany. You have to realize that, before the Holocaust became worldwide public knowledge, many if not most of the West's population was anti-Semitic. It was not only common, it was very socially acceptable.
Some individuals were outraged of course, and not everyone was antisemitic. But there were not enough people at that time who were both organized and courageous to take a stand against Hitler's treatment of the Jews. Individuals did, here and there, take action and protect/save Jews from being deported and murdered, but they were the exception rather than the rule.
Also remember that some people in France, Italy, Yugoslavia, Greece, Poland and Hungary as well as the Soviet Union and the Baltic States helped with the Holocaust, as they were antisemitic as well, or stood to profit from the Jews deportation.
It is important to understand that Hitler did not invent antisemitism in Europe. There is a long history of antisemitism in Europe, dating back hundreds, if not a thousand years. Spain and Portugal expelled Jews in the 1400's, and other countries did, too, from time to time, both before and after the 1400's. Russia has a history of antisemitism, as does France.
When Hitler came to power, there were serious economic problems in Germany, a depression, high unemployment, and inflation so severe that it was said that it took a bushel basket of money to buy a loaf of bread. Some of Germany's economic woes were part of a general, world-wide slump, but an additional problem for Germany was the incredible debt it had to pay the winners of World War I, the United States, England, and the other allies in that war.
So, the people of Germany were suffering and when Hitler came along with a "solution" that placed the blame on Jewish people, he was drawing on a long history of antisemitism, not a new idea. History tells us that not everyone along with the program, but many people were desperate and likely to be antisemitic anyhow.
Another factor was the gradualism of Hitler's campaign to rid the country of Jews. First Jewish people lost jobs, then they had to wear yellow stars to identify themselves, and so on. Before anyone had a chance to really assess what was happening, Jews were going to concentration camps and dying.
While I have never seen a newsreel with Hitler speaking, I have read that he was a mesmerizing speaker, and that people were eaily persuaded by him. This also might have been a factor in the ease with which he did what he did.
I should also mention that antisemitism still exists, in Europe, in the United States, and in other countries as well. Could this happen again? I would like to think it could not, but there certainly are no guarantees.