To single someone/something out for criticism or ridicule; to make an example or victim of someone (idiomatic).
新しい政策はメディアに槍玉に挙げられた。
The new policy was singled out for criticism by the media.
彼は不祥事で槍玉に挙げられ、辞任を迫られた。
He was singled out for the scandal and was pressured to resign.
古い軍記には、敵を槍玉に挙げる場面が何度か描かれている。
Ancient war chronicles often depict scenes of spearing enemies (literal sense).
To pierce with a spear (literal sense), often used in literary or historical contexts.
戦場で敵を槍玉に挙げる描写が物語に出てきた。
The story contains depictions of spearing enemies on the battlefield.