This is so wrong, its not expensive to bribe politicians so higher taxes wouldn't stop this at all. The problem is that its possible to bribe politicians, meaning government has too much power, taxes would make that worse not better. And even more important most bribes doesn't come from individuals, it comes from super PACs and corporations, and those would exist regardless how much you tax rich people.
What you need is a less centralized government so its harder to bribe a few key people to get what you want, and a more direct democracy that can eliminate politicians that takes bribes.
When voters can't punish bad politicians since the incumbents has so much power to draw voting lines and decide who is on the ballots then corruption will always escalate out of control.