I was once listening to a ruler of a non muslim nation saying that " I will give the power to the people of this country" And i said to myself that "no you will eat it up all by yourself'. Is this regarded as something that shows support for democracy?and is it regarded as going against the Shariah even though the leader was of a nation that was originally disbelieving.
TL;DR: It seems awfully strict to consider it disbelief. For it to be disbelief, one would need to be convinced that God's ruling is incorrect, and have an intention of disbelief.
A question was asked about the rulings that contradict [the meanings of] God’s Revelation.
They summarize Shaykh Al-Fawzan: The Religion of Tawhid, 116, as:
Changing God’s Revelation with other rulings [that are not derived from revelation] constitutes an act of disbelief. This act evicts one from the fold of Islam.
And respond to it as follows:
... the person who does this is not to be accused of disbelief, unless s/he is convinced that God's ruling is incorrect and his ruling is correct.
... disbelief requires the intention of disbelief, and not just absentminded words or deeds
They derive this from Qur'an 63:1 where the mere actions of belief by hypocrites were insufficient to render someone a believer:
When the hypocrites come to you, [O Muhammad], they say, "We testify that you are the Messenger of Allah." And Allah knows that you are His Messenger, and Allah testifies that the hypocrites are liars.
From this, they surmise that mere actions of disbelief would be insufficient to render someone a disbeliever.