Complex sentence: The dominant political ideology of the era was Deng Xiaoping Theory, which was accepted by the party in 1978, and he served in various leadership positions, although his paramount power was not overtly reflected in his formal titles.
Split into simpler sentences: The dominant political ideology of the era was Deng Xiaoping Theory. Deng's political ideas were accepted by the party in 1978, and he served in various leadership positions, although his paramount power was not overtly reflected in his formal titles.