Does Anchor Text Affect Page Rank?

I've been waffling on enough about my sites that I've looked at in which links don't seem to be followed because they use strong keywords in anchor text. But, is there any truth in it?

It's long been recognised that this technique can be used to increase search engine ranking. Search on "click here" (with or without quotes!) and you will find the first result is an adobe page, without either word on it. So it is apparent that anchor text does play a huge part in Google's algorithm.

So if a site had thousands of links for an important keyword then it would seem logical that the site would be top for that search. But, is that natural results or spamming?

Click here does appear in an astonishing number of searches – but mostly within phrases. It's not a high power keyword. And in all likelihood, most 'natural' links don't use a high proportion of keywords. So it would see possible that it could be used as a flag. So I will investigate the issue further.

So could there be a difference between linking to a site with Click Here and Mortgage Rates - other than what SEO experts currently tell us?