It is true that eventually, the Orthodox will be a majority. However, that will be a couple generations from now, and it is hard to tell what will happen.
Charedim are growing the most quickly, but the attitudes of charedim are changing — some are becoming more moderate (“the new charedim”), and some are becoming more extreme (Bet Shemesh, the renegade Burka women, etc.). So they will probably be quite a diverse group themselves by 2050 or whatever.
The dati leumi, which range from LWMO to chardali in their hashkafa, are also growing quickly. They will not be the most numerous Orthodox group, but they will be a large block. And of course they fight in the army, they have guns, they believe in their way of life, and seriously, they would rather die than be ruled Iran-style by a council of charedi gedolim.
Chilonim and sephardim may not grow as fast but they will still comprise a significant part of the population, as will Arabs (unless something happens, like a big war or, c”v’s, a Palestinian state). They, along with the dati leumi and many of the charedim, will not allow democracy and civil law to be replaced by an authoritarian Torah state.
So we will likely have some combination of traditional Torah law and civil law, in a democratic framework. Only with Moshiach will it likely be possible to institute pure Torah law (and democracy will probably still play some role, if necessary — will Moshiach even decide when the local parks will close, for example?)
Most Orthodox rabbis today, not just Chabad and other kiruv people, understand that forcing people to obey Torah will just turn them off, and make them hate everything Yiddishkeit stands for. We need to encourage people to make teshuvah through reasoned arguments, and most of all through kiddush Hashem, the power of a good example.