expression, godan verb (-ru)
take a firm stand; argue vigorously
Used when someone presents a strong, well-prepared argument or position, often in a debate or dispute. The image is of deploying a battle line of arguments.
彼は会議で論陣を張って、新企画の必要性を訴えた。
He took a firm stand at the meeting and argued for the necessity of the new project.
野党は国会で論陣を張り、法案に反対した。
The opposition party argued vigorously in the Diet and opposed the bill.