To adduce (something) as a reason, excuse, support etc.
To make a claim as justification or proof; to make an assertion without proof.
To believe (something is reasonable) and argue (for it); to advocate.
To be in opposition; to contest; to dispute; to vie; to quarrel; to fight.
To be in debate; to engage in discussion; to dispute; to argue.
To struggle or exert oneself to obtain or retain possession of, or to defend.
contend with: To try to cope with a difficulty or problem.