The case of Maurice is an interesting one, and also one where many rumors and common misconceptions persist.
One is the assumption that Maurice was saved from persecution as a Jew thanks to Hitler's intervention. That is actually not the case.
Emil Maurice had one Jewish great-grandparent: His paternal great-grandfather Charles "Chéri" Maurice, a well-known, successful and highly respected theater owner and -manager in his day, who converted to Protestant faith in 1832. This made Emil Maurice what was known as an "Achteljude" ["one-eighth Jew"] in the terminology of the day. Achteljuden were not affected by the Nuremberg laws and could become civil servants, military officers and even members of the Nazi Party. However, one thing they could not become was SS officers, as these had to prove "Aryan" ancestry as far back as 1750.
In the late Twenties, there had been prolonged troubles between Hitler and his erstwhile best friend Maurice. This had to do, among other things, with Maurice's engagement to Geli Raubal (it was more than a mere affair) and the danger of his ancestry becoming public. Following a successful labor court lawsuit by Maurice against Hitler over the matter of his being laid off as Hitler's driver, Maurice was dismissed from the SS in 1928, although he remained a Party member.
Hitler's and Maurice's ways parted for several years until the well-known dramatic changes of 1933 gripped Germany.
With the Nazis firmly in power, many open accounts with political opponents and undesirable elements within the movement were settled. Maurice started to fear for his life and was especially shook up by the fate of his good friend and former RFSS Erhard Heiden, who was kidnapped from a café and vanished. (His dead body was found months later.) These fears were well-founded: Heydrich and Himmler had set their sights on him, Himmler being especially eager for revenge, as Maurice, during his time as the first Inspector of the SS, had at one point disciplined and temporarily suspended him.
At this point, Maurice's father gave his son a bit of pragmatic and, it turned out, wise advice: "Go into the lion's den". Maurice sought out a meeting with Hitler and in April 1933, the two men had a long talk in which they settled their differences and mutually admitted their fault in the past mistakes and misunderstandings. (Obviously, Geli Raubal, being dead by the time, no longer stood between them...)
Unlike the extremely vengeful and merciless Stalin, Hitler often showed an oddly soft side when it came to the "old fighters" of the early days and the talk was of immense benefit to Maurice: Much to Himmler's chagrin, he was accepted back into the SS and swift promotions would follow: Sturmbannführer and Obersturmbannführer in 1933, Standartenführer in 1934 and Oberführer in 1939. He would also become a city councillor for Munich (1933), a deputy in the Reichstag (1936) and the chairman of the Munich Chamber of Trade (1937). These posts may have held little political or executive power, but they came with prestige and financial compensation. Also, Hitler regularly supplied his watchmaker's business with orders for gold watches intended as personal gifts.
Most importantly, Himmler was made personally responsible for Maurice's safety: Had Maurice suffered some mysterious "accident", it would have been Himmler's neck in the noose. There can be little doubt that, had Hitler and Maurice not made peace, he would have been among the victims of the following year's Röhm purge.
As if that wasn't big enough a thorn in Himmler's eye, Maurice got newly-engaged in 1935 and requested a wedding permit, as all SS officers were required to do. Himmler, who could not bear the thought of the part-Jewish SS officer fathering children who would thus become additional "non-Aryan" members of his "SS family", tried to prevent this and saw it as a new opportunity to dismiss Maurice from the SS once again. Unsurprisingly, he was once more overruled by Hitler's decision: With Hitler's blessing, Maurice got married. Adding insult to injury (in Himmler's eyes), Hitler even paid the newlywed couple a personal visit in their appartment and discreetly left them 1,000 Reichsmarks as well.
Himmler's entries in the secret file relating to this matter are worth reading:
"1. According to his genealogical table, SS-Standartenführer Emil Maurice is of indubitably non-Aryan descent.
2. On the occasion of SS-Standartenführer Maurice's wedding, for which purpose he had to submit his genealogical table, I have stated to the Führer my point of view, this being that I was of the opinion that Maurice would have to leave the SS.
3. In this single, exceptional case, the Führer has decided that Maurice, as well as his brothers, were allowed to remain members of the SS, as he had been his very first escort and he as well as his brothers and the entire Maurice family had served the movement in its first, and most difficult years, with rare bravery and loyalty.
4. I [i.e. Himmler], decree that neither is Maurice to be entered into the Sippenbuch [familiy book] of the SS, nor that any descendant of the Maurice family may ever be accepted into the SS.
5. One copy of this protocol is submitted to the Head of the Rasse- und Siedlungshauptamt for his information and with the request of treating it most strictly confidential; only the Head of the Sippenamt is to be involved.
6. For myself, as well as all for all of my successors as the Reichsführer SS, I state that only Adolf Hitler himself had and has the right to decide on exceptions for the SS in matters of blood. No Reichsführer SS, be it now or for all future, has the power to grant exceptions in the demands the SS places on blood.
7. I bind all of my successors to the strictest adherence to the position laid down under number 6."
Nos. 4 through 6 were added on Himmler's urging. If he absolutely had to accept Maurice as an SS member, he at least had the small consolation of denying any future descendants of the family the entry into his "black order"...
For German-speaking readers, I would like to recommend Anna Maria Sigmund's book "Des Führers bester Freund", which is a biography of Maurice as well as a study of his relationship with Hitler and the whole Hitler-Raubal-Maurice triangle.