old school tie; loyalty to one's alma mater
Refers to the strong sense of solidarity and mutual support among graduates of the same school, often with a critical or negative connotation about factionalism.
Strong old-school-tie feelings remain in that company.
It's a problem when personnel decisions are made based on school connections.
学閥 refers to the clique or faction itself, while 学閥意識 is the consciousness or sentiment of loyalty to that clique.
派閥意識 is a broader term for factional loyalty, not limited to school ties.
Compound of 学閥 (がくばつ, 'school clique') and 意識 (いしき, 'consciousness').