Is Charity Navigator politically biased?

I went to Charity Navigator to check out Prison Fellowship, since I am interested in the fate of the kids whose parents we must send to prison. It got high marks for transparency and doing the project (as best as I can understand their site) and very low for "financial" so the ended up with just two stars.

So I decided to look for a higher ranked outfit that does similar work. I searched simply for "prison" and this is what I got:

http://www.charitynavigator.org/index.cfm?keyword_list=prison&Submit2=GO&bay=search.results

Now a scroll through the results reveals an interesting pattern. The highest grades go for outfits that have a particular political slant, no?

Those merely working locally get lower grades. Those pushing the "intelligent" agenda seem to get the top marks.

Worth considering, I think.