Some would argue that "we" have already taken the 1st steps towards a federal police force by essentially demanding that local & state law enforcement focus on illegal immigrants.
The mission to address illegal immigrations is a federal one being addressed by federal agencies (ICE... and others)... but "we" want city police departments to supplement immigration enforcement... and "we" want to send the National Guard (i.e. military) to support immigration enforcement. Some even want active duty armed forces doing the same.
If a city doesn't want its police to pursue immigration enforcement, they are labeled a "sanctuary city" and face the possibility of losing some of all federal assistance....
>>> the first steps to a federal police force have been taken... how far it will go is the question... <<<
Interesting that you bring that up (forgot about it)
This is exactly what "Defund the Police" is about.
They shouldn't be responding to things such as immigration, domestic disputes, homelessness "street cleaning", cats stuck in trees.
But it will also take a culture change of the people. For how long has the threat "I'll call the Police!" been hurled for almost any dispute.