Complex sentence: In the same vein, Browder himself picked up hints from Socialist Party leader Norman Thomas that joint work between Socialists and Communists might be possible on specific issues, in reply to which Browder issued a letter formally proposing a large scale united front of the two organizations.
Split into simpler sentences: In the same vein, Browder picked up hints from Socialist Party leader Norman Thomas that joint work between Socialists and Communists might be possible on specific issues. Browder wrote Thomas a letter formally proposing a large-scale united front of the two organizations.