Senate opinion on the treaty (Treaty of Versailles and proposed League of Nations) was divided into three distinct views:

   1. Internationalists. Democrats loyal to Wilson wanted the treaty to be ratified in its original form without any amendments or reservations; some within this group were receptive to a small number of minor changes.

   2. Reservationists. This group claimed to be in favor of the treaty, but only after including a series of reservations prior to ratification. Senator Lodge of Massachusetts was the leader of this faction and was personally 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. The Reservationists were the largest of the three factions.

   3. Irreconcilables. Isolationist senators, including Robert M. La Follette of Wisconsin, William E. Borah of Idaho and Hiram Johnson of California, opposed the treaty and American entry into the League of Nations under any circumstances. They had counseled against entering the war in the first place and now opposed participation in European affairs. 

Below were the positions taken and the statements that members of the factions would have made in 1918.

Strong Internationalist Positions 
 
The League of Nations has come about by no plan of our conceiving, but by the hand of God who led us into this way. We cannot turn back. We can only go forward, with lifted eyes and freshened spirit, to follow the vision. It was of this that we dreamed at our birth. America shall in truth show 
the way. The light streams upon the path ahead, and nowhere else. 
 
Any changes to the League Covenant are a rejection of the League. 
 
It is my purpose to vote against the pending resolution of ratification incorporating reservations adopted by a majority of Senators. I believe the Senate is about to vote on an alleged resolution of ratification, a resolution that does not ratify but which, in fact and in legal effect, constitutes a rejection of this treaty. 
 
 
Limited Internationalist Positions 
 
The combined pressure of the world’s nations will prevent the unlikely possibility that the U.S. could be forced into a war against its will. 
 
 
Mild Reservationist Positions 
 
Nations horrified at their losses in the Great War will be careful in negotiations, and good outcomes will result despite flaws in the League Covenant. 
 
It is necessary to remember that the lack of such a league in 1914 threw the world into the chaos of this war… The question of this hour therefore is not whether a beautifully phrased and perfect document has been written, but whether it is the best hope we have. 
 

Strong Reservationist Positions 
 
If the League ever adopts a plan to reduce armaments, the U.S. must reserve the right to increase its armaments without the consent of the council whenever it is threatened with invasion or engaged in war. 
 
Specific and limiting changes to the Covenant must be made to protect U.S. interests. 
 
The League would threaten U.S. sovereignty by requiring the U.S. to follow directions from an international body, so all decisions of the League must be considered suggestions only. 
 
 
Irreconcilables 
 
We cannot send our representatives to deliberate with the representatives of the other great nations of the world with mental reservations as to what we shall do in case their judgment shall not be satisfactory to us. 
 
They tell us the League of Nations will be a great brotherhood of nations assembled; and that when those nations are assembled together they will be a body devoted to the service of God and man without a single selfish thought or a single iniquitous motive. Yet, at the close of the war, many of those same countries that we are now told will liberate nations and bring democracy to the people of the world seized every foot of territory that was held by helpless people anywhere. 
 
Shall we go to the League to help make decisions, and then if we think that decision works for peace, join with our allies, but in case it works for war, withdraw our cooperation?