"Put not your trust in nobles, or in the son of earthling man, to whom no salvation belongs." (NWT)
"We must obey God as ruler rather than men" (NWT)
"blah blah blah no part of this world blah blah blah" (NWT)
Now let's look at modern representational democracies. How about we go with the US, since it's the political system I'm most familiar with. Who is the boss in the US? The President? Screw that. That guy is my employee. Like my janitor. I have delegated my authority to him. I am the boss--and so is every other citizen here. I did not run for this office. I didn't seek it at all. I automatically gained it when I turned 18. I have it whether I choose to exercise it or not.
Let's say my road has potholes. I'd really like someone to come fix them. If I'm a JW, I could wait for God's Kingdom to come 'round and fix them, but all indications are that it's going to be a while before an angel comes down with a bucket of tar and some gravel, so I might as well fix it myself. How can I do that? Well, other people live on this road too. It's not really fair if I have to go fix it completely out of my own pocket. They should help too, if they want it fixed. We're going to have to pool our cash to get this done. And then we can pay someone to do it who actually knows what they're doing. If I can get everyone to agree to pitch in for this, then we each only have to pay a fraction of the total cost, and everyone benefits. And we can all decide what kind of road material we'll use, since we all paid, and we can all decide who will do the work. Better yet, we could just all agree to choose ONE person who can do the research and make those decisions, since we all have jobs and lives. We could even pay that person.
I'd also like to make sure my kids grow up well educated. But, geez, I don't know the first thing about teaching kids! Wouldn't it be nice if we could build some building where teachers could teach my kids? But other people have kids too. I shouldn't have to foot the whole bill.
Apply the above to whatever you'd like. Public health. Property rights. Criminal justice. Etc. Etc. Etc.
Does anyone really think that it shows lack of faith in God's Kingdom to help decide how immediate issues are handled? Is it really putting our trust for salvation in "earthling man" if we just want him to pick out a road material? Or build a school? Does anyone really think that Jesus expected his followers to be completely uninvolved in local and regional government when he said they were no part of the world? We have the birthright, whether we want it or not. And the authorities, apparently, were placed in their relative positions by God. And the Witnesses sure don't have any qualms participating HEAVILY in the judicial branch of government.
The no voting-no running for office-no joining political parties shtick is illogical and indefensible, but it's a JW teaching, so does that surprise you?