Is there an adjective describing some person or group of people who blindly follow a leader figure, especially with negative connotations?

I'm looking for a word describing those who act like sheep to the shepherd, blindly following the leader figure, without considering their own actions. If I could conceive of such a word, I might make it something like "igorical" (reminiscent of Igor, who blindly follows his mad scientist leader).

Example of use (applying to behavior):

It is in such igorical behavior that such an election can arise.

Example of use (applying to people):

It is in the existence of such igorical people that such an election can arise.

A relatively recent coinage is sheeple. It means exactly what you want, albeit a noun rather than an adjective.

The word appears to date back to the 1940s, but I've come across it several times in social media lately, usually in the formulation "Wake up, sheeple!"

It hasn't made it to spellcheck yet, though.

The obvious, off-the-cuff answer is "lemming" or "lemming mentality," but I suspect that's a little cliché and/or informal for your purpose.

sheeple or sheople People who are meekly submissive or easily swayed (Sheep + people)

Sheeple (a portmanteau of "sheep" and "people") is a derogatory term that highlights the passive herd behavior of people easily controlled by a governing power which likens them to sheep, a herd animal that is easily led about. The term is used to describe those who voluntarily acquiesce to a suggestion without critical analysis or research in large part because the majority of others possess a similar mindset.

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“acolyte” in the sense of follower, has been used for this purpose