Fact: Black hole bodies absorb matter.
Fact: Each galaxie has a super massive black hole bodie at it's center.
Fact: Galaxies on occassion collide, and absorb each other, forming a larger galaxy.

Assumption: 
When two supermassive black hole bodies meet, it is reasonable to assume they absorb each other, creating a more massive super massive black hole body, with stronger gravity than both had before collision.
Assumpton:
When two similar sized galaxies combine, eventually they must return to the size both were initially as more matter is pulled into the supermassive black hole.

If all of the above is correct, and it likely is, then this is further support for galaxian shrinkage over time, creating larger distances between galaxies, and resulting in red shift.

This would help replace the idea of an 'expanding universe'.