Final answer:
President Woodrow Wilson faced opposition from the U.S. Senate, lack of support from the League of Nations, and absence of a public referendum in his efforts to ratify the Treaty of Versailles.
Step-by-step explanation:
President Woodrow Wilson faced several barriers in his efforts to ratify the Treaty of Versailles. One of the main obstacles was opposition from the U.S. Senate, particularly from Republican senators who had reservations about the treaty's provisions. Senator Henry Cabot Lodge issued a list of fourteen reservations, most of which centered on the creation of the League of Nations.
Another barrier Wilson faced was the lack of support from the League of Nations. Some senators feared that joining the league would cost the United States its sovereignty and tie the country into foreign disputes. They also objected to Britain and France's desire to control the league.
In addition to these barriers, Wilson also faced the absence of a public referendum. The treaty required two-thirds approval by the U.S. Senate for ratification, and Wilson's efforts to turn public support into a weapon against those in opposition were hindered by his deteriorating health after suffering a debilitating stroke.