Immediately after the battle Cato returned home with despatches. We have
dim and uncertain information that he took the field once or twice again,
but his career as a soldier was practically ended.

From this time to his death, forty years later, Cato was the leading figure
on the stage of Roman politics. In season and out of season he attacked
abuses or innovations in speeches addressed to the senate, the people, or
the courts. Soon after his return from Thessaly he struck a heavy blow at
the unrepublican honor-hunting among the magistrates, of which the example
had been set by P. Scipio Africanus. Most provincial governors drove their
subjects into war, sent lying despatches home about their victories, and
claimed a triumph. In 190 Cato attacked with success the proposal to grant
a triumph to Q. Minucius Thermus, who had already triumphed over the
Spaniards as praetor, and after his consulship in 193 had fought against
the Ligurians. Cato's next victim was his former commander M'. Acilius
Glabrio, who came forward at the same time with Cato, Marcellus (a son of
the captor of Syracuse), L. Cornelius Scipio Nasica, T. Quinctius
Flamininus (the conqueror of Macedonia) and Cato's friend L. Valerius
Flaccus, as candidate for the censorship of 189. Cato by his violent
speeches procured the trial of Glabrio for appropriating the plunder
captured in Thessaly, and himself gave evidence concerning some property
which had disappeared. Glabrio denounced Cato as a perjurer, but yet
retired from his candidature. On this occasion Cato and Flaccus failed,
Marcellus being elected as plebeian and Flamininus as patrician censor.

In the next year (188) Cato acted in the senate with the party which tried
unsuccessfully to refuse the triumph to the two consuls of 189, M. Fulvius
Nobilior and Cn. Manlius Vulso, the former of whom had gained none but
trifling advantages over the Aetolians, while the latter had disgraced the
Roman name by making war without authorization upon the Gauls of Asia