Final answer:
The loss of colonies after the Peninsular War and internal strife, including the rise of socialist and anarchist movements, along with a coup leading to a right-wing authoritarian regime, significantly weakened Spain's political power.
Step-by-step explanation:
Several events had a negative impact on Spain's political power, most notably the loss of its colonies. The Peninsular War, which began when Napoléon occupied Spain in 1807, led to the formation of local juntas in its American colonies, paving the way for self-rule and fueling desires for independence. The early 19th century saw Spain losing most of these colonies, inducing a period of internal strife and civil wars.
Throughout the early 20th century, Socialist and Anarchist movements gained momentum among the Spanish populace, culminating in the establishment of a republic in 1931 following the king's abdication.
This period was characterized by deep societal divisions, agrarian reform, and church-state separation. However, the lack of stable governance and the rise of conservative powers led the country into a right-wing authoritarian regime after a nationalist coup, signifying further decline in democratic political power.