You are going to see stories like this and this reporting that Guam has elected its first Republican non-voting representative to Congress since 1993. Journalists desperate for something to write about while we await returns have landed on this factoid.
The DrsC spent a year as visiting faculty at the University of Guam in the mid-1980s. While that hardly qualifies us as experts, we at least called Guam home for a year.
At that time, Guam had Republicans and Democrats but the so-called "parties" had little to do with the groups with those names in the States. Basically, they were coalitions of ruling families in opposition to each other who contested for control of the island's government structure and handed out patronage when successful.
Guam natives, who call themselves the Chamorros, tended to be allied with one coalition or the other, most often by either blood or marriage. Guam politics are dynastic, "Republican" James Moylan just defeated "Democrat" Judith Won Pat who has the same family name as Guam's first representative in DC had several decades ago.
"Liberal" and "conservative" tend not to mean much on an island whose economy is largely dependent on the U.S. military which maintains large bases there. The other main source of revenue is tourists from Japan who treat Guam as a cheaper-to-reach sub-tropical substitute for Hawaii.
Bottom line: That Guam elected a "Republican" may not mean what us mainlanders would tend to conclude.