Final answer:
Most Democratic-Republicans supported the French Revolution because they saw it as a continuation of the struggle for liberty and an extension of the American revolutionary ideals. They were unfazed by the Reign of Terror, interpreting the violence as a necessary step to remove the vestiges of monarchy and aristocracy in France. The relationship between the U.S. and France, forged in the American Revolution, also underpinned their sympathetic stance.
Step-by-step explanation:
Most Democratic-Republicans supported the French Revolution because they identified with the revolutionary cause and the struggle against monarchy, seeing it as a continuation of the American fight for liberty. The revolution's initial phases resonated with their principles, such as the establishment of a constitutional monarchy and then a republic. Moreover, the attachment between France and the United States was historically significant due to the alliance during the American Revolution. However, the Federalists perceived the violent course the French Revolution took, particularly during the Reign of Terror, with great concern, fearing it could threaten the stability of the American republic.
When France declared war on Great Britain, the French Revolution further polarized American politicians. Federalists argued that the violence of the Revolution was evidence of anarchy, while Democratic-Republicans maintained that the radical changes were necessary to eliminate monarchy and aristocracy. Party politics greatly influenced the American response to French events. The Democratic-Republicans, often strongest in the South and amongst immigrants, maintained that the violence was a regrettable but necessary part of the revolutionary process of casting off monarchism and that the fate of France's nobility served a 'greater cause'. They marked their support with symbolic gestures like donning tricolored ribbons and singing revolutionary songs, embracing the spirit of the movement.