Darth Sidious is a monstrously powerful Dark Lord of the Sith who secretly controls both Sides of the Clone Wars and pretty much every corporation in the Galaxy… but the Jedi wouldn’t be able to tell you that, because they couldn’t work out who the mysterious Sith Lord that Dooku spoke of was until it was far too late. But how did Palpatine stay hidden for so long and why couldn’t the Jedi sense him? Well the answer goes back much, much further than you might have thought. So hit that subscribe button and lets get into it.
So the first major reason for Palpatine being able to hide is his proficient use of Buried Presence. Buried Presence was a sort of branch of the Force Stealth ability and allowed Palpatine to mask his signature in the force to anyone around him. This included the Jedi Order. It forced him to bury his Dark Side presence and force abilities deep inside of him, ready to burst out when the time came. Over countless thousands of meetings, nobody was able to identify Palpatine as the Sith Lord controlling the Senate mostly thanks to this ability. Not to mention, Palpatine always portrayed himself as weak and fragile wherever he would go. A sweet old man like him couldn’t do any harm right?
The next reason though is much darker and goes back thousands of years. Many hundreds of layers beneath the cold and creaky catacombs of the Jedi temple, laid an ancient Sith Shrine built by an unknown man. This shrine was known as the “Shrine in the Depths”, and was a tremendous source of Dark Side energy on Coruscant, spreading the darkness out over a huge area. Interestingly, it was actually built on top of a Light Side force nexus in order to corrupt the force energy flowing out of it. The plan certainly worked. For these reasons, the Jedi chose to build their own temple on top of it, in hopes of stemming the flow of the dark side… As you can imagine, this was a horrible idea, since it only served to cloud their own judgement and fuel Palpatine’s ability to hide himself.
This also compounded with the Jedi Losing their affinity for the force near the end of the Republic because of going so many years without an enemy. Mace Windu even considered going to the senate about this because it was such a devasting thing for the Jedi to face.
Now another thing that added onto Palpatine being able to hide himself was that the Jedi were just plainly unfamiliar with the Dark Side of the force by that point. Jedi younglings and Padawans had been taught for so long by that point to avoid the Dark Side at all costs and never seek it out. This resulted in a lot of the Jedi being very unfamiliar with the Darkness. By the time of the Clone Wars, the Jedi likely believed that the Sith would be bold, arrogant and flaunting their powers across the Galaxy. They weren’t prepared whatsoever for a stealth takeover. Yoda certainly learned his lesson with that after Order 66, because he allowed Luke Skywalker to enter the Dark Side Cave on Dagobah, showing him the dark side enough so that he wouldn’t be tempted by it.