I’m hardly an expert, but perhaps the question is “which one?” If you look at the Chabads like the Lubavitchers awaiting Rebbe Mendel Schnerson’s reappearance as the messiah (he died about 10 years ago), that might be one strain, i.e., the dynastic rebbes. Then again, if you go back to the 17th century, nearly all of East European Judaism was messianiac, viz Shabbetai Zevi claimed he was the messiah in 1665 and most of the Jews in Poland-Ukraine were ready to pack up and head to Palestine. Major difference (near as I can tell!) is Christian messiah (Jesus) is a spiritual entity whose return means you-know-what. Jewish mossiach is a real living human with a lineage to David, learned in the law, and a military leader, basically a military leader to defeat the ever-irritating Gentiles who kept on invading and conquering Palestine going back the Egyptian New Kingdom, then the Assyrians, then the Babylonians, then the Persians, then the Greeks, then the Romans, then the Byzantine Empire, then the Muslims, then the Crusaders, then the Ottoman Empire. One related question: Once the Muslims captured Jerusalem in 638, the Jews were invited back. Why did they wait 1,300 years when Theodore Herzl gave them the “all clear”?