He received an Associate in Applied Science degree in business administration from Northern Marianas College and studied communications at the University of Hawaii at Manoa.

[3] Demapan served in the Northern Mariana Islands House of Representatives during the 19th and 20th Commonwealth Legislatures.

[4] On October 4, 2017, Demapan announced his candidacy for Delegate to the United States House of Representatives in the November 2018 election.

[5] He faced incumbent Delegate Gregorio "Killi" Sablan, an independent, in the forthcoming election on November 13, 2018, who won reelection by a wide margin.

[9] In the 2022 general election, Demapan ran for an open seat in the Northern Mariana Islands Senate.