I've heard this question asked many times here in Geneva, and the answer depends on who you ask. People working to improve labor rights are going to give you a very different answer from those who advocate for stronger protections for child soldiers, for example.
Here's my response:
It doesn't make much difference at all. Human rights transcend partisanship. It takes broad bi-partisan support to ratify a human rights treaty: 67 senators have to vote yea. And there is bi-partisan support for human rights. Maybe not 2/3 of the Senate... but still.
And anyway, most of Human Rights USA's work is in the courts. So the changing makeup of the Congress has little direct impact on the cases we are litigating.