One objection the reservationists had regarding the treaty was that it contradicted the power of Congress to declare war.
When the treaty arrived in the Senate in July, Democrats mostly supported the treaty; however Republicans were divided. The “Reservationists,” which were led by Senator Henry Cabot Lodge, claimed to be in favour of the treaty only if certain reservations, or alterations, were adopted prior to ratification. Senator Lodge of Massachusetts was the leader of this faction and was dedicated to frustrating the aims of his rival, Wilson. Other senators in this group sincerely favored the treaty, but wanted some modification to protect vital American interests.