Here in Germany, there was a well-known group led by a man named Cameleddin Kaplam who had declared himself 'Ameerul Mu'mineen'.

Answer

Voting is not an Islamic system of appointing rulers. It is a kuffaar system. Nevertheless, it is not kufr to employ this method when there is a need. There does sometimes arise a dire need for acquiring methods of the kuffaar to achieve an Islamic objective. For example, if the army of a Muslim country is Deeni conscious and desires to establish the Shariah as the law of the land, then it will be Wajib (compulsory) for the army to stage a coup and appoint a pious ruler to rule the land according to the Shariah.

Similarly, if a genuinely Islamic political party utilizes the system of voting to gain power in a Muslim country, then it will be incumbent to do so in order to establish the Law of the Shariah. Once they have grabbed the reigns of power, then it will be incumbent to operate only Islamic systems of appointing leaders.

Those who claim that the commission of a sin is kufr, are morons. The belief that a sin is not sinful is kufr. Furthermore, voting is a method of securing legitimate power in a situation where no other method/system is available. In such a scenario it will become necessary to employ even kuffaar methods to bring about the domination of the Shariah.

When the mushrikeen of Makkah had intended to attack Madinah, Rasulullah (sallallahu alayhi wasallam) accepted the advice of Hadhrat Salmaan Faarsi (radhiyallahu anhu) to adopt the kuffaar (Persian) method of digging a trench around Madinah to block the kuffaar attack. Despite this method being hitherto unknown to the Arabs and being a kuffaar method, Rasulullah (sallallahu alayhi wasallam) adopted it.

What is kufr, is to intentionally displace the Islamic system of government and replace it with a kuffaar system as is the current position in every Muslim country where all the rulers are kuffaar of the murtad category because they have cancelled the Shariah willingly.

It is laughable for a man to declare himself Ameerul Mu'mineen when he is at the mercy of the kuffaar – when he has no country to rule. Only a moron does something so silly. He made a mockery of himself.