Set up by supporters to help Mr. Pence defray the costs associated with responding to the investigation of the special counsel, Robert S. Mueller III, into Russian interference in the 2016 presidential election. he majority of the trust’s cash came from three donors who each gave $100,000 — Michael K. Hayde and Laura Khouri, real estate executives from Southern California who have donated nearly $3 million to national Republican candidates and groups since the beginning of the 2016 election, and Herbert Simon, a mall developer from Indiana and the owner of a professional basketball team who has donated more than $560,000 in that time, primarily to Democrats. A pair of $50,000 donations came from the Michigan investor Ronald Weiser, a former Republican Party official and major donor who in 2017 attended a dinner with Mr. Pence at the vice president’s residence, and the real estate developer Leo F. Wells III. The trust was created in late 2018 by James D. Atterholt, who served as trustee. He had worked as chief of staff for Mr. Pence during his time as governor of Indiana.