And more than that, he is intervening on behalf of his older brother.
Sanders, who missed out on taking the Democratic nomination from Hillary Clinton, has recorded a brief but heartfelt campaign video aimed at voters in Witney, Oxfordshire, that talks up the attributes of his brother, Larry.
Larry Sanders, who has lived in the UK since 1969, is standing for the Green party in the constituency, which will elect a new MP on 20 October to replace David Cameron, who quit the Commons last month.
The Green party and the Liberal Democrats are making considerable efforts to produce some sort of upset in Witney, where the Conservative candidate, councillor Robert Courts, remains the strong favourite.
The party is hopeful of improving on its distant third place in Witney in 2015, with the party’s leader, Tim Farron, having visited three times during the campaign.