No one is “allowed” to take power. There is a constant struggle for it. Leftists have been losing that struggle because they don’t get enough votes.
Dems move right because it is a politician’s job to cater to their constituents regardless of their ideology. If there are fewer leftist constituents then the politicians move right.
Another bad faith argument.
You know that “majority” consisted of Sinema and Manchin and in addition to that, most big changes require a super majority.
But you’re just trying to cause infighting.