Pulitzer displayed a flair for reporting. He would work 16 hours a day—from 10 AM to 2 AM. He was nicknamed "Joey the German" or "Joey the Jew". He joined the Philosophical Society and frequented a German bookstore where many intellectuals hung out. Among his new group of friends were
Joseph Keppler and
Thomas Davidson.
He joined the
Republican Party. On December 14, 1869, Pulitzer attended the Republican meeting at the St. Louis Turnhalle on Tenth Street, where party leaders needed a candidate to fill a vacancy in the state legislature. They settled on Pulitzer, nominating him unanimously, forgetting he was only 22, three years under the required age. However, his chief Democratic opponent was possibly ineligible because he had served in the Confederate army. Pulitzer had energy. He organized street meetings, called personally on the voters, and exhibited such sincerity along with his oddities that he had pumped a half-amused excitement into a campaign that was normally lethargic. He won 209–147.
His age was not made an issue and he was seated as a state representative in Jefferson City at the session beginning January 5, 1870. He had lived there for only two years. He also moved up one notch in the administration at the
Westliche Post. He eventually became its managing editor, and obtained a proprietary interest.
In 1872, Pulitzer was a delegate to the Cincinnati convention of the
Liberal Republican Party which nominated
Horace Greeley for the presidency. However, the attempt at electing Greeley as president failed, the party collapsed, and Pulitzer, disillusioned with the corruption in the Republican Party, switched to the
Democratic Party. He served as a delegate to the Missouri Constitutional Convention in 1874, representing St. Louis; and in 1876 gave nearly 70 speeches in favor of Presidential candidate
Samuel J. Tilden. In 1880, he was a delegate to the Democratic national convention and a member of its platform committee from Missouri.