When the revolution of 1848 broke out Bamberger took an active part as one of the leaders of the republican party in his native city, both as a popular orator and as editor of the Mainzer Zeitung newspaper.

In 1849 he took part in the republican uprising in the Palatinate and Baden; on the restoration of order he was condemned to death, but by then with other leading revolutionaries like Germain Metternich, Louis Blenker, and Franz Zitz he had escaped to Switzerland.

He was elected a member of the Reichstag, where he joined the National Liberal Party, for, like many other exiles, he was willing to accept the results of Otto von Bismarck’s work.

In the German Reichstag he was the leading authority on matters of finance and economics, as well as a clear and persuasive speaker, and it was chiefly owing to him that a gold currency was adopted and that the Reichsbank took form; in his later years he wrote and spoke strongly against bimetallism.

He was the leader of the free traders, and after 1878 refused to follow Bismarck in his new policy of protection, state socialism and colonial development.