In the nineteenth century there was an element that helped to suppress the mystical lore.
Within the strong rationalistic tendency of the age, many influential people (such as the authors of the most important books of Jewish history) were fiercely antagonistic to any mystical approach and tried to disparage it and even deny its existence in the past.
The apologetic mood of the time demanded hiding these shameful parts of Judaism and trying to forget them entirely.
The result has been a general misunderstanding of the role of the Kabbalah, and of the mystical experience altogether, in Judaism.
The truth is that the Kabbalah permeates every aspect of Judaism, and the "esoteric wisdom" has been a basic ingredient of scripture, ritual, and prayer.
Even many popular expressions, in Hebrew but also in the colloquial Yiddish, have their source in the Kabbalah.
Although a careful distinction was maintained throughout the centuries between the nigleh and the nistar, between the revealed and the hidden aspects of the religion, it was never a division within the people or within Judaism as conceived by its greatest authorities.
The Shulhan Arukh, the great work that has become the fundamental halakhic text for all of Jewry, was written by Rabbi Joseph Caro, a sage whose authority rested not only on his very broad learning but also on his many-sidedness and mystic insight.
He wrote other books of halakhic procedure and law, exegeses on Torah and the like, and in addition he wrote a treatise called Maggid M'esharim, which was certainly a kabbalistic work and showed him to be a man who had mystical experiences and visions.
Those of his generation who heard about his revelations were inclined to say that it was the voice of the Mishnah speaking from his mouth.
–Rabbi Adin Steinsaltz
From "Mysticism in the Jewish Tradition," in On Being Free by Rabbi Adin Steinsaltz