「」？
What percentage of winning an election is about how you look?
Literal
Election [target-に] win [purpose-には] "appearance" [subject-が] what percent?
An elliptical headline-style question. ~には ('for X-ing' purposive contrastive) frames the goal. 見た目 ('appearance, looks') is a casual noun from 見る + 目 — literally 'seeing eyes' = 'how it looks to the eyes.' Quoted in 「」 for emphasis. 何割 literally 'what tenths' — 割 is the unit used in Japanese for 10% segments (compare 3割 = 30%). Typical tabloid headline style.