Of course, that is only my interpretation.

I wasn't suggesting that self-proclaimed Christians should be forbidden from participating in politics, but that they must refrain from it if they really are to be followers of Christ.

You are right that I was thinking primarily about the larger context--national or, in the U.S., a state. In local matters like roads, water/sanitation, etc. it might seem ludicrous to say a Christian should offer no input, but even the most local politics soon turns to issues of power over people: what should be taught in school and permissible books, what medical services public facilities will provide, what businesses should be allowed to operate and where, etc., not to mention money--taxation and how public money will be spent.

All politics inevitably represents money and power. Beyond that, it is simply the case that Jesus was, it seems to me, radically apolitical, so to be a follower of him means being apolitical--something I, by the way, am not. While the teachings of Jesus do define how I seek to live my life otherwise, however, I have never once claimed to be 'a Christian'--with all the implications that carries regarding the kind of humble, other-centered person anyone making that claim must be.