Were Hitler's anti-Jewish sentiments known at all to those who voted him to power in 1933?

In 1923, Hitler was part of the Bavarian communist party. He took part in their failed coup in Munich, which led to his arrest and him leaving the party and joining the NSDAP instead, which at the time was an up and coming ultra-nationalist party with very similar ideas to that of the communist party (except for being German nationalist rather than seeking eventual merger of Germany with the USSR).

Both parties (as was common at the time in Germany as well as other countries) had their own security force and "action groups" to protect their own members during rallies and harass and sometimes murder political opponents.

Those groups formed the core of the group that staged the failed communist coup in Munich that got Hitler sent to prison where he wrote Mein Kampf, and the SA and SD of the 1930s when Hitler became Reichskanzler after the NSDAP came to power.

As to his anti-Semitic views, those were widely known and shared by a large part of the German (and indeed the European and US) population. Mein Kampf was a best seller, national socialist parties existed in many other countries with very similar agendas (up to and including later on seeking merger of their countries with the Third Reich), and anti-Semitic speeches did not suddenly start after the 1932 elections, but were common before that.

The post-WW2 idea that somehow a small group of nazis staged the holocaust without knowledge or approval of the general population is blatantly wrong. While most people would probably have been horrified had they known the exact details of what went on in places like Bergen Belsen and Dachau, those same people didn't mind at all that the "evil Jews" were removed from their societies and killed. Thus also the idea of large scale operations in Europe to save Jews and hide them from the Gestapo and other police forces are much overstated. While such things did exist, they were small, not just for lack of people but also to maintain operational security (more people involved, greater chance of leaks and discovery, and a lot of such cells were indeed ratted out to the Gestapo from the inside).

To what degree would his anti-Jewish sentiments have reasonably been known to those who voted him to power in 1933?

Very well, and in fact many believed the same things themselves due to the eugenics movement.

Eugenics

While it has always been controversial, it was still a well enough accepted philosophy that many nations made laws based on the concept that genetics determine character, and that some races were genetically inferior to others. From Wikipedia:

Eugenic policies were first implemented in the early 1900s in the United States. It also took root in France, Germany, and Great Britain. Later, in the 1920s and 1930s, the eugenic policy of sterilizing certain mental patients was implemented in other countries including Belgium, Brazil, Canada, Japan and Sweden.

Politically, the movement advocated measures such as sterilization laws. In its moral dimension, eugenics rejected the doctrine that all human beings are born equal and redefined moral worth purely in terms of genetic fitness. Its racist elements included pursuit of a pure "Nordic race" or "Aryan" genetic pool and the eventual elimination of "unfit" races.

Hitler subscribed to this philosophy, and like many others of that time his writings were no more controversial than other proponents of eugenics. Wikipedia:

Adolf Hitler had praised and incorporated eugenic ideas in Mein Kampf in 1925 and emulated eugenic legislation for the sterilization of "defectives" that had been pioneered in the United States once he took power. Some common early 20th century eugenics methods involved identifying and classifying individuals and their families, including ... racial groups (such as the ... Jews) as "degenerate" or "unfit", and therefore led to segregation, institutionalization, sterilization, euthanasia, and even mass murder.

This was not only something people knew about Hitler, it was actively being practiced in the country prior to the holocaust, and many other countries had laws discriminating based on race supported by the idea of superior genetic stock.

Yes, his anti-jewish sentiment was well known to those who voted for him, in fact many of them subscribed to the same belief system.

The question is easily answered: Everyone knew. He wrote "Mein Kampf", which was publically available. He preached his views right from the beginning. But politically, that was no problem for him.

Since answering the question is just a matter of looking it up in Wikipedia, I guess the author of the question is rather asking "If everyone knew about Hitler's sentiment towards Jews, how come he still had so many followers?". I will try to answer that question.

See, being openly anti-semitic only became a problem after the end of World War 2. Before that it wasn't really an issue. It is quite comparable to what politicians do nowadays. Saying stuff like "Let's get rid of all the Jews that are stealing our jobs and our money" is not too different to "Let's send all the Mexicans back to Mexico" or "Let's get rid of all the muslims". Only the horrors of WW2 and the holocaust made the first statement a taboo. Because of what happened during that time, Jews now have some form of protection against hate speech.

Hitler's statements might have alienated some of his potential voters but for many this was a reason why they voted for him.

Since nowadays it is (in many countries legally) not allowed to hate Jews, populist politicians are now attacking other minorities. In the USA it's mainly Muslims and Mexicans, in the UK it is Rumanians and the Polish, in Central Europe it is the refugees. In Russia it is the Jehovas Witnesses.

Some politicians even go as far as to suggest that the army should shoot at people who try to cross borders illegally.

Hate speech against Jews and blacks is very taboo, but hate speech against religious minorities (e.g. Muslims, Yehovas whitnesses, Sikhs or Mormons) or other ethnical groups (e.g. Mexicans) is no problem.

We often think of ourselves as so much better than people from other areas or times, but in fact we are the same. Our faults only differ slightly.

Yes. Hitler's book, "Mein Kampf" was the second best selling book in Germany in the early 1930s (after the Bible), and laid out his views in excruciating detail. Most people had access to the book, not all read it, but it (and Hitler's other views) were featured in newspapers such as the Volkische Beobachter.

Perhaps the more important question, as Denis pointed out, was why people voted for Hitler knowing these views. The issue is that being "anti-Semitic" was not nearly as pejorative in the 1930s as it might be today.

Hitler basically ran on an "anti-foreign" platform; tear up the Versailles treaty, whose repayment provisions were choking the German economy, and overstep the territorial limitations embodied in that treaty (re-militarize the Rhineland, unite with Austria, and more). And on the same subject, Germany would settle accounts with those of its citizens that presumably benefited from World War I and contributed to Germany's defeat by aiding "foreign interests," thereby administering a "stab in the back" to Germany. Such views, while abhorrent, were not too far from what was then the mainstream of German politics.

So did the Germans of the time "know?" Yes, or at least they should have known by reading the book or at least about it. Did they care? Perhaps not. Or perhaps to the extent that they did "care," Hitler's views would have worked in his favor.

Antisemitism was a major election platform for Hitler along with nationalism. Jews were traditionally (even preceding the Middle Ages) restricted in their professions, barred from crafts and locked into money-lending and legal business. After centuries if not millennia of this lock-in, there was a significant correlation of those businesses and Jewish proprietors.

In this climate, there would have been absolutely no point in hiding general Antisemitic leanings for a politician: in a democracy the voting majorities would rather consider this an advantage.

Ask the average person on the street today how much he likes big lawyers and their world and business styles, and how much he likes big corporations and their world and business styles, and you won't get much enthusiasm. A century ago, this was summarized as "Jewish World Conspiracy" and had a reasonable number of scapegoats people were ready to vilify accordingly available.

War reparations and the consequential inflation made a lot of people poor who did not have the capabilities or foresight or planning to rescue their savings by timely conversion into tangible goods.

Even before the world wars, at a time of comparative prosperity at the end of the 19th century, France had the Dreyfus affair which amounted to punishing Jews just because.

The dire economic conditions Germany was under made both money and law professions more visible to the average citizen, with either of them strongly and with some statistical justification being associated with Jews.

Even today, a simple "our country belongs to us, root out the foreigners occupying it" platform, with foreigners loosely associated with "people other than ourselves" (never mind how long their ancestors may have lived longer in the country than you), will garner enough votes to be troubling or even majority-taking. Take a look at Trump in the U.S., the Front National in France, the AfD and Republicans in Germany, the FPÖ in Austria and so on.

People know where this leads but the first impulse is to take out any problems on "the others" when a country has real or perceived problems.