That is the big problem here, from my perspective.
When I read in Lawrence that the US Supreme Court had used European law to justify their opinion, I was flabbergasted.
I expected the SCOTUS justices to use some subterfuge explaining away their controversial decision, but I was taken aback at their brazenness in invoking foreign law.
The way I see it, if President Kerry appoints a couple of new justices to the SCOTUS, the new-and-improved SCOTUS will feel free to use European law and the UN Human Rights Charter as de facto world constitutions, overriding our humble but time-tested US Constitution.
The two issues that are the most improtant for me are getting conservatives on the judiciary and continuing to hunt down and kill jihadists. Everything else flows from that.