A wealthy businessman with tea party ties confirmed Sunday that he is mounting a primary challenge to House Speaker Paul D. Ryan, saying that after donating to the Wisconsin Republican’s past campaigns he feels “betrayed” by the speaker on trade deals and immigration. The businessman, who is not yet revealing his identity, promised that his run will “shake up the establishment in a profound way,” according to a political consultant close to the prospective candidate. The emergence of a viable Republican challenger in Wisconsin’s 1st Congressional District is the culmination of a monthslong recruitment effort by tea party activists who...