This New York Post article claims that he "championed left-wing causes", but does not provide any evidence for that. However, it does reveal him to be a Neocon warmonger. Snip:

Routh is also a staunch supporter of Ukraine and Taiwan in their respective conflicts against Russia and China. He claims on X that he tried to “sell” the idea of having former Afghanistan troopers fight for Ukraine in Russia, but was denied multiple times before giving up after six months.

He also visited Kyiv and claimed that he would be willing to fight on the front lines, if he were permitted to.

He was also a supporter of nuclear warmonger Nikki Haley's presidential campaign.