2016 Indiana Republican presidential primary

By late April, Cruz and Kasich had both been eliminated from getting 1,237 delegates, but they still had a chance to accumulate enough delegates to force a contested convention in Cleveland. Realizing this, Cruz and Kasich attempted to focus their efforts in different states, with Cruz challenging Trump head-to-head in Indiana and Kasich challenging Trump head-to-head in Oregon and New Mexico. However, the alliance was tenuous at best, with Kasich telling voters in Indiana the next day to still vote for him and Cruz downplaying the alliance later in the week; it also met with disapproval from 58% of Indiana voters.[1][2][3]

Indiana was seen as the final state for the "Stop Trump" movement. Indiana, whose delegates were awarded winner-take all statewide and by congressional district, was seen as essential to denying Trump the 1,237 delegates needed to secure the nomination.[4] Following the Acela primaries, Cruz attempted to bolster his chances by announcing that, if nominated, he would name Fiorina as his running mate.[5] Fiorina had served as a Cruz campaign surrogate since March after suspending her own presidential campaign in February and Cruz hoped that Fiorina could help his campaign in Indiana and her home state of California.[6] On April 29, 2016, Governor Mike Pence of Indiana, who eventually became Donald Trump's running mate, announced that he would vote for Cruz in the primary election.[7] However, Cruz's posturing and endorsements proved to be insufficient, as Trump handily won Indiana with 53% of the vote, despite being outspent by a margin of more than 4–1.[8] Cruz lost Indiana by a wide margin to Trump (53% to 37% with Kasich at 8%) and subsequently dropped out of the race.