Simple fact is purists are not popular. Very few get elected. Not a winning strategy to use filters for purists.
Unless you enjoy being a pitiful minority in Congress.
Nancy Pelosi keeps her minions in line. And she’s more of a Marxist.
Obviously you didn’t read my statement — democrats are purists and they win because they stick together. So, purists do win. But republicans are a mix of Rinos, democrats who call themselves republicans and conservatives. And we have seen what your apparent philosophy of giving in and not being purists has done to the country.