Through the states.
1) Get voter ID, end same day registration, require residency to register to vote as well as proof of former address and verification that said voter is off the rolls of their former home state. In otherwards, end the Democrat fraud.
1) Get right-to-work in all states possible. Limit public union collective bargaining, make them pay for their fair share of health insurance and pension. End state collection of union dues. In otherwards, kill the Democrat, union funded ATM machine.
Other things are to use the courts to states maximum benefits, sharply limit federal grants to states and localities (to cut the strings and limit unfunded mandates), welfare reform, defund groups like Planned Parenthood. I’m sure there are many other ways to put the hurt on the Dem party while quarantining the Feds out of state business as much as possible.