The votes against them are splitting among various candidates, which likely allows the ruling party, with its strong support, to win.
こんにちは！
ご質問ありがとうございます。
ご質問について、いくつか言い方が考えられますが、例えば、
The opposition candidates haven’t managed to come together, resulting in too many running in the single-member districts. Although there's public dissatisfaction with the ruling party, the votes against them are splitting among various candidates, which likely allows the ruling party, with its strong support, to win.
とすると、『[野党](https://eikaiwa.dmm.com/uknow/questions/95484/)の候補者が一本化できておらず、小選挙区で野党候補者が乱立しています。世間からの与党への風向きが悪いにも関わらず、反与党の票や浮動票が分散してしまい、結果的に組織票を持つ与党が当選すると思われる』となります。
参考になれば幸いです。
日本 
