I completely agree that Eretz Yisroel should be governed by Torah and Halacha, but as of right now, it is not. Until mashiach comes, I doubt it will (but I will still hold out hope). Rather than throw out the baby with the bath water, we have to deal with the situation we have. We have a secular government and we, as believing Jews, should use the system that's in place as best we can to accomplish what we know to be right.
At this moment we have a problem with missionaries. How, with a secular government, can we keep most or all of them out? We are losing Jewish souls by the droves. I am not a politician, I am a religious counselor/mentor (counter-missionary), but I do know that we need laws that will protect the precious Jewish neshamas that are here as best we can, understanding the the secular government doesn't give a white about them.
I don't think anyone has said this yet so here I go:
In many ways, "democracy" is the new Avodah Zara of the Jews.
The only thing we can practically do now is to try and make our voices heard to the politcal powers that be and to try to point out how tainted some of our politicians at high levels are because of their benfits to aligning to Christian causes.
This won't happen by making massive protests but I would suggest a letter campaign (not email nor fax) to our religious politcians of all parties and to numerous Rabbanim of influential persuasions.
And then there is Israel's "Supreme" Court.........................
I forgot to mention: don't forget to daven a little harder.
Mamlakhtim are the worst because they think the current government IS a representation of Torah.