It was designed that way. Hell, originally you bought your seat by spreading patronage around in your state legislature which then
appointed you to the Senate. No man who wasn't rich would stand a chance. In the 19th c. the saying arose "It is easier for a camel to pass through the eye of a needle than for a poor man to enter the Senate" and it's still true today. That's not by accident either. The Framers of the Constitution were a relatively rich lot and they designed the Senate, using the House of Lords as model, to ensure that people of their class would always have a veto power over anything proposed in the "lower" house that was popularly elected. It is only a slight exaggeration to say that, under the Senate's original rules, one US senator could stop anything the House of Representatives had passed unanimously - in practice he would need a couple of confederates. The Presidency was initially a figurehead position, the real power was in the Senate. The President has one veto which is rarely exercised; but w a membership of 50 states, the Senate has 100 vetoes which are constantly being exercised. Even though the upper house has been "democratized" by requiring popular elections for Senate seats, it is still composed overwhelmingly of wealthy persons, reflecting the preference of the upper classes for people like themselves to keep a monopoly on the Senate's veto power.
If you can always say
what may not happen in your country's legislature, it comes to the same thing -if you guard and exercise this power jealously- as always being able to say what
must happen. So it was that the founders of republic created a dictatorship of the wealthy class, while appearing to create a government that enacted the popular will and derived its legitimacy from the popular will.