It is very difficult to assess exactly what the McCann's position is in the public eye.
I have noticed that even within the Daily Mail readership, there seems to be more support than I previously thought. Most replies to McCann articles were anti-McCann, but this assesses determination to post over real analysis of beliefs. Perhaps the [ censored word] are more angry, vindictive and blaming than the pros are relaxed, excusing and forgiving, meaning that [ censored word] are more likely to post. We cannot know.
But since the Mail altered its approve/disapprove voting system where it now takes just a button press to vote, most 'pro' posts have a good majority of green thumbs up whereas most 'anti' posts have a majority of red thumbs down.
Previously they only listed the reds minus the greens as a single total, but now you can see that some posts have many votes in favour of the McCanns. Given that the Anti sites (who have much larger memberships than any pro site) regularly have threads to 'get the vote out' on Mail and other threads, I tend to believe that there is a solid majority of "Very pro, mildly Pro, generally forgiving and don't really cares" over the people who believe that the McCanns are culpable for anything more than rather doubtful childcare.
The Mail is hardly representative, as comments are screened before being printed on the web, so it is of little consequence.
A more fairer sample of public opinion can be seen on the yahoo comments pages, where there is moderation, but opinions across the spread of views are allowed.
There are of course some nutters from both sides of the fence, and their posts and the posters themselves invariably get banned.
So I suggest you have a look at those to see 'public opinion'.