I think even without bribery, if the allegation of what he did is true, he will get impeached, and political supremacy in Central will dilute the votes. UDA will likely be left with 25%, but if a stronger Kingpin (Sad Kenyan politics) emerge, Gachagua maybe able to sell his 50-60% to opposition (Kalonzo/Kioni). I don't think Gachagua and Ruto will see eye to eye from the things I have heard from trusted sources, but in Kenya anything is possible!