In 2018, Castro visited the first in the nation New Hampshire primary state, and delivered the commencement address at New England College in Henniker, New Hampshire, on May 12, 2018. Castro stated that he would make his decision on whether to run in 2020 after the November 2018 mid-term elections. On December 12, 2018, Castro announced the formation of an exploratory committee. The next day, during an episode of "The Late Show with Stephen Colbert", Julián's brother Joaquin (during a joint appearance by both brothers) stated that he confidently believes that Julián will be running for president.