There appears to be a fear, among politicians , of taking a well thought out position on most anything. Everything seems to be measured by it's immediate effect and reception. And, ultimately the persuasion of block votes.
The non-advocacy position is most notable in cultural and economic matters.
The current marriage issue is a good example of non-advocacy. The majority of the citizens, nowadays, feel a marriage is only between a man and a women. That is all that should be natural and legitimate. Any other kind of sexual arrangement is a perversion, and perversions can be of various sorts. The Republican Party makes a terse statement of that fact, but no advocacy. It may be a part of their platform, but it is a mum and defenseless position. You will have a hard time finding a standing Republican politician that will elaborate on the issue of marriage being only between a man and a woman.
Same with key economic issues. Those issues that would make a difference in peoples lives. More and more people are becoming concerned about the concentration of wealth and inequality of income. Of course, this has been building for decades, and is even a worldwide phenomenon. It demands an urgent response, but the politicians are reticence to discuss details. Every utterence seems to be measured for a political response. There is no free dialogue. It is not only the polilticians, but media outlets as well. They are senstive to retain power and position. Yet, by and large, unused power and position.
I watched a program host ask a candidate for President in 2008 if he favored breaking up the big banks. He never got an answer! Fear of the block votes?
We are ruled by block votes and money. The concentration of economic power lends itself to block voting. The half-century change in values lends itself to block voting.