As the soul-bride ji our only bed-fellow is Akaal. As a follower of SRM our only bed-fellow should be the person we are married to. Unless of course we are kids and share beds with brothers or sisters.
Really I do not think Sikhi is aligned with any political party, but has to align with a very special sense of dharma which may at time be consistent with political parties and other times not.
Here are some interesting thoughts about social justice and Sikhism. I read this to mean that we as Sikhs make the choice to follow dharma because it is right and not because it is government policy.
http://www.sikhphilosophy.net/hard-talk/30414-socio-economic-study-wealth-poverty-sikhism.html
Socialism expects from each according to his ability, to each according to his need. Sikhi expects us to earn an honest living and share with the less fortunate, strictly as a matter of moral choice and not as an edict of government. Is that socialism? So why could a Sikh not be a member of the Republican party, and be a voice of righteousness within that party?
I think this is actually a very complicated question and socialism has to be explored in theory and practice in some depth before making this kind of connection.