Well what exactly do you mean by rise to power? They have remained an independent state since then, save a few brief run ins with the Soviets and Chinese.

If you're asking why they never expanded into an empire again it was mainly due to a lack of centralization. After Kublai Khan there was a lot of warring between Mongolian lords for power. They also didn't have the expansionist culture that they once did. The ruling class took a lot from the Chinese who were the polar opposite of expansionist.