I don't think so. Although there is a slight chance he could be related to Paxton and is "carrying on the family cause", you don't have to be a relative of someone to share their views. He could have studied Terra Prime and sympathized to a degree or could have developed his militant philosophy on his own. Besides, their goals were different. Paxton was xenophobic and wanted to rid earth of aliens while Marcus was going for a pre-emptive strike against a foreign power.