why can't that be dealt with at the state level?
why is it necessary to continue and continue to expand the federal government....that is not what this country was founded on.
ARTICLE 1 - SECTION 8 - US CONSTITUTION
POWERS OF CONGRESS,
"To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes"
Rand Paul doesn't have a choice to abdicate his responsibility as a US Senator, and defer the power to regulate interstate commerce to "locals", whatever "locals" means. Its his job to regulate interstate commerce, if he wants to be a US senator.
No one is expanding the federal government on this issues, as I understand it the bar needs to be set higher for safety and performance rules so less miners are killed.
Unless Kentucky is an extremely lazy state, they have their own mine regulators and inspectors. The Feds are just supposed to make sure that the States are all competing on essentially the same level; that there's a national baseline of safety and performance standards in the coal mining industry.
As for the nature of your question about liberals wanting the feds to take over everything, I can't speak for anyone else, but I reject that premise. I can't think of any interactions I have with the federal government on a routine or daily basis, and I'd like to keep it that way. I want the roads, the parks, the law enforcement, the water, the garbage collection, and intrastate criminal law to be done at the state and local level.
The only thing the feds really do is cut SS checks to grandma, pay grandpa's doctor, fund some infrastructure projects, support a global military posture, and set some modest national baseline standards for interstate commerce, environment, and labor. None of which I have to deal with routinely, or which affects me, on a day to day basis.