Q. 3) Is one obliged to vote in and for such government?

A. See question 1188 where we mentioned the different Torah sources and mitzvos involved in establishing a government. Rabeinu Yona (Shaarei Teshuva 3: 168) writes vehemently; “When the heads of the community congregate together with the people with the purpose of serving Hashem and they accept enactments to do mitzvos… the individual who separates himself from them is seen as a Poresh M’darkei Tzibur… and shows himself as unwilling to participate in their mission and be written in their writ etc. However, Horav Shlomo Miller’s Shlit’a opinion is that in practice it depends on the circumstances and needs of each particular case. In principle, he maintains that although it may be a given right and a mitzva to vote in community matters, it is not in general an obligation to do so.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a