Are there unelected hereditary nobles somewhere in the US that is entitled to having a seat in congress and can vote against laws being passed?

Nope. I don't think so, not even the length of the term is the same.

In the US our unelected hereditary nobility just buys candidates.

unelected hereditary nobles

Let's break down what Senators are:

> Unelected

In most states a single party will always win statewide elections, so our Senators are what I'd call "marginally elected" since they only have to face a quiet low-turnout primary election and then they sail to an easy re-election. They're nearly always guaranteed to win their primaries as long as The Party supports them, and they'll do so as long as you're loyal to The Party agenda.

> Hereditary

Many of them come from generational wealth, and a few suspiciously just happen to become wildly wealthy while in office, including through their stock trades, which has been decided to be 100% not illegal even when they know things the public does not know.

> nobles

Ours are called "elites," but most things are the same - they tend to all have gone to the top 2-4 colleges, and you can't 'break into' this set unless you were born into old money. Seems close enough from the perspective of those of us who aren't nobles or elites.

So, you can think of the Senate as the House of Lords lite.

And yet all of your objections apply to us in equal measure. Almost as though hereditary nobles don't have much to do with them.