Actually this is a better example of how to use the money.  The MLK thing when the NFL and private organizations did it was fine.  When DOT got involved that was just vindictive and probably unconstitutional.

But Homeland security IS defined in the constitution as one of the few responsibilities of the federal government.  In that, they have every right to move the money to places where it will do the most good.  Harboring illegal aliens, while not explicitly aiding our enemies, does abet them by hindering the federal government from performing their task.  And if not for the passivity of the activity (just not enforcing laws instead of out right breaking them) would be declared unconstitutional.

DC is a bad example because by simple legislation, Congress can force them to.

But let's take San Fran instead.  You are right in your fears.  And any sane person would be as well.  But a child is not a sane person.  A child wants a simple world where they get their wants when they want them.  Until they are an adult, it is the responsibility of the parent - the adult - to tell them no.  Once they are an adult, there is nothing the adult can do to change that attitude if it has not changed by then.  So is the parent then obligated to continue to indulge the child's every whim just because the child never matured and took responsibilty upon themselves?

I say no.  It is called tough love.  And at that time, when the child becomes an adult, the parent should say no by withholding support. Forcing the child to face the consequences of their irresponsibility.  This is the same situation.  If the government cannot get the city to act in a responsible manner as regards to the law, then withholding the financial means for them to continue in their childish ways is the only option left open.  If the child has any sense at all, they will come to the conclusion that the world does not revolve around them, and in order to live in a civil society, all must follow rules.  And all must contribute to the safety and security of the society as a whole.

These cities are merely being petulant children.  They did not get their wants when they wanted them, so they are holding their breath.  What they dont realize is that they have to breath, we dont have to fund their tantrums.  They will either mature and join the society, or suffer as a petulant child does who has been cut off of the gravy train.