This politician served on the Dillingham Commission, where he advanced the nativist ideas he proposed in The Great Peril of Unrestricted Immigration. George Frisbie Hoar sponsored a bill named for this politician that countered the Mississippi Plan and guaranteed the rights of African Americans to vote in the South. This politician chaired the committee that investigated war crimes in the Philippine-American War. While serving as Chair of the Senate (*) Foreign Relations Committee, this politician opposed a resolution of the Shandong Problem in the sixth of fourteen namesake “resolutions.” This Massachusetts senator led the moderate faction between the Irreconcilables (10[1])and Woodrow (-5[1])Wilson on the question of ratifying the Treaty of Versailles. For 10 points, name this Massachusetts senator who led the opposition to American entry into the League of Nations. ■END■ (10[1]0[2])