I want to describe someone who fanatically follows one of the following:
Basically, someone who will agree with their government/party/country regardless of what actions/decisions they make.
I was thinking of words such as zealot, follower, etc..
The word most similar to what I want is slang: sheep.
example in a sentence:
Elise constantly agrees with anything the liberal party says and does without having any personal opinions; she is but a sheep.
While not a noun, the term knee-jerk is often applied to the category descriptor to demonstrate blind allegiance
(Of a person) responding in an automatic and unthinking way: knee-jerk radicals
[ODO]
Possibly partisan
a person who takes the part of or strongly supports one side, party, or person; often, specif., an unreasoning, emotional adherent
[Collins]
The term chauvinist is also used to indicate fierce commitment to a cause or point of view
A person displaying excessive or prejudiced loyalty or support for a particular cause, group, or gender: what a male chauvinist that man is
[ODO]
When coupled with an aggressive, often militaristic stand, the term jingoist may be used
Extreme patriotism, especially in the form of aggressive or warlike foreign policy.
[ODO]
Sheeple is an interesting portmanteau that is a widely accepted term. An equivalent synonym/doctrine is "conformist."
[Sheeple] is used to describe those who voluntarily acquiesce to a suggestion without critical analysis or research. Wikipedia
It often portrays criticism in the tendency of crowd thinking and hive mindset. Here is a neat (perhaps very satirical) comic from xkcd to consider:
I think you have already answered in your question by yourself, - 'a blind follower.
A Yes-man :
a person who agrees with everything that is said ; especially : one who endorses or supports without criticism every opinion or proposal of an associate or superior.
Extract from http://www.lemauricien.com/article/political-fiction-yes-man
Elected in the same constituency as the Leader, the Yes Man is an expert in menial work. He started by carrying posters for a former banished young stud of the same faction. Despite being relegated to the sidelines, this has-been has managed to feed off the generosity of the party by aligning himself with another fervent patriot and organising PR coups where he gets to promote himself more than the real talents. However, let us not wander too far from our luminary presence.
If such a person is actually part of the state, then they're a functionary or (more strongly) apparatchik. Allegorically, they are a drone or myrmidon, both words with connotations of insect colonies.
Otherwise they would be a zealot, true believer, or partisan who had drunk the Kool-Aid (referring to the use of poisoned Kool-Aid (Flavor-Ade) in the Jonestown cult mass suicide / murder).
Sheep. Just like that animal that moves wherever its herder takes it, no questions asked.
Ideologue is probably the word your looking for, since your specifically looking for a word that describes blind allegiance to ideological or political forces.
Partisan also is a pretty good word for what your describing itself. Typically its used now by politicians or media organization to slander each-other though, so its true meaning has become muted over the years due to over use.
Sycophant is also a pretty good word to describe people like that if they have something to personally gain or lose.
It also has a connotation of someone who is slanderer, accuser, calumniator, etc.
While it deals specifically with Communism, Apparatchik seems to qualify.
Conformist was always my favorite term for it.
a person who behaves in accordance with prevailing standards or customs and typically dislikes or avoids unconventional behavior https://www.merriam-webster.com/dictionary/conformist
It objectively describes those that comply for the sake of following, not unlike the poster's religious and governmental examples, but without espousing conviction or zealotry.
I would call such persons 'the immature'. For 'errare humanum est' (evb. makes mistakes), and 'individualism' does count but we must not neglect the opposite (community; a man is 'zoon politokon' - a man shall be tolerant but watchful activist, too).
Would 'assimilate' (as in conform) be an appropriate synonym for what you're trying to say? Assimilating culture, policies, the 'new agenda'...
Servile
Fanatical minion would be the only term I could come up with to describe blind followers of a political or religious dogma. Sorry that it is actually two words. This is totally different from a minion fanatic which is someone obsessed with characters from the movie "Despicable me"
A "statist" is an advocate of statism, which is, in turn, the allowance of control into the "the hands of a highly centralized government, often extending to government ownership of industry." Contrast with "anarchist."
It sounds like you are looking for a pejorative to describe a single member of a group, who blindly follow. Lemming is sometimes used for this purpose.
sheepas a slang form, Sheeple is in fact a valid term that the public can easily relate to while having a civil discussion.