Wikipedia
The Herodians were a sect or party of Hellenistic Jews mentioned in the New Testament as having on two occasions — first in Galilee, and later in Jerusalem — manifested an unfriendly disposition towards Jesus (, ; ; cf. also , , ). In each of these cases their name is coupled with that of the Pharisees.
According to many interpreters, the courtiers or soldiers of Herod Antipas ("Milites Herodis," Jerome) were intended; others argue that the Herodians were probably a public political party, who distinguished themselves from the two great historical parties of post-exilic Judaism (the Pharisees and Sadducees) by the fact that they were and had been sincerely friendly to Herod the Great, the King of the Jews, and to his dynasty (cf. such formations as "Caesariani," "Pompeiani").
It is possible that, to gain adherents, the Herodian party may have been in the habit of representing that the establishment of a Herodian Dynasty would be favourable to the realization of the theocracy; and this in turn may account for Pseudo-Tertullian's (Adversis Omnes Haereses [1,1)) allegation that the Herodians regarded Herod himself as the Messiah. The sect was called by the Rabbis Boethusians as being friendly to the family of Boethus, whose daughter Mariamne was one of Herod the Great's wives.
Professor Robert Eisenman of California State University, Long Beach argues that Paul the Apostle was a member of the family of Herod the Great. Professor Eisenman makes a connection between Paul and an individual identified by Josephus as "Saulus," a "kinsman of Agrippa." Another oft-cited element of the case for Paul as a member of Herod's family is found in where Paul had written, "Greet Herodion, my kinsman."