New York Senator Thomas Dewy was running for president against Franklin Roosevelt and sought to attract Jewish voters by supporting the establishment of a Jewish state in Palestine. The Republican platform adopted at the national convention subsequently called for the implementation of the Balfour Declaration and condemned Roosevelt for failing to pressure the British to fulfill their promise. The Democrats subsequently adopted a pro-statehood position at their convention. The appeal to Jewish voters did not resonate for Dewey, who lost their vote by a margin of 90%-10%. This is the relevant excerpt from the Republican platform:
In order to give refuge to millions of distressed Jewish men, women and children driven from their homes by tyranny, we call for the opening of Palestine to their unrestricted immigration and land ownership, so that in accordance with the full intent and purpose of the Balfour Declaration of 1917 and the Resolution of a Republican Congress in 1922, Palestine may be constituted as a free and democratic Commonwealth. We condemn the failure of the President to insist that the mandatory of Palestine carry out the provision of the Balfour Declaration and of the mandate while he pretends to support them.
Source: Republican Party Platform of 1944,
The American Presidency Project.