What remedies are available in the last instance?

Voting RightsAct (1981), Subchapter IV Recounts and Appeals, p49.

1573. Denial of petition; appeal of denial to Trial Division.

(b) Appeals may be had in the manner prescribed in subsection (a)of this section from any decision of the Election Commission concerning aruling of an election board with respect to a challenge affecting theacceptability of a vote or votes.  Apetition hereunder for appeal shall contain the information specified insection 1571 of this chapter for a petition for a recount.  A decision of the Trial Division in favour ofthe petitioner may have the effect of disallowing the challenged votes butshall not halt or delay balloting or counting and tabulating.

http://aceproject.org/ero-en/regions/pacific/PW/palau-voting-rights-act-1981/view