One of the basic principles of democracy is that nobody but the voter him/herself needs to know who he/she is voting for. Neither one's spouse, parents, employer, spiritual leader or anybody else has the right to know one's political conviction.
For Westerners this may seem obvious, because we grew up with this right in a culture which places great emphasis on the inviolability of the individual. But for many who grew up in non-democratic societies, introducing such a priciple may be a long and arduous process. Especially in traditional societies, in clan societies and in societies in which men generally make decisions on behalf of their wives, it may be seen as quite a radical change to insist on such secrecy.
Next chapter: Rule of Law