Although Buddhism is the predominant religion of Thailand and has the official sanction and support of the government, there is freedom of religion for all people in Thailand. There is no government opposition to the open and free practice of Christianity or other religions. However, Thai Buddhists who become Christians (or Muslims or some other religion) often face opposition from their families and friends and experience social pressure to return to Buddhism. This pressure can be very strong during family and community activities such as weddings, funerals, and neighborhood events. To not participate in the Buddhist or spirit-worship aspects of these activities can be misunderstood as disloyalty to family or nation.
About 95% of Thai are Buddhist. 4% are Muslim and about 1% are Christian or other. Only about 0.58% would be counted as Protestant, the majority of which would probably fall under the category of broadly evangelical.
Thailand is a constitutional monarchy. The King of Thailand has a significant moral influence over the country but the day-to-day affairs are handled by a prime minister and Parliament.