One of the basic principles of discussions is that for winning it is important that you are the one who frames the questions. We see this in elections times and again.
A good example were the economic policies of Reagan and Thatcher. They had some luck that the end of a recession seemed to confirm their policies. But much of their success was due to pure bluff. It also helped that after two decades of leftish policies people were ready for something new. But one thing is certain: they changed the political dialogue. Since then leftish demands like equality and fairness are taboo and rightish issues like lower taxes and privatisations are the norm. And we see that even successful leftish politicians like Clinton and Blair are following those norms. Interestingly they typically show a split personality: in their talks they question those norms but in their actions they are often even more fanatic than their right-wing colleagues.
However, people prefer the real stuff. If rightish policies are the norm they will show a preference for rightish politicians.
That brings me to Israel. In Israel establishing settlements has been the norm for several decades now. And leftish politicians have often done that even more enthusiastically than their rightish colleagues. So when Netanyahu rejected the two-state solution and when he denounced Arab participation in the elections he stated things that implicitly have been accepted as the norm by all sides for decades. He just showed the courage to say it explicitly.
Doing that he brought the parties on the left in a difficult position. They could denounce him. But if someone would challenge them they wouldn't have an argument as they had de facto supported similar policies in the past. They are incapable of bringing an alternative. Think of it as something similar to Bush sr's "Read my lips, no new taxes". It was an irresponsible statement and Bush had to swallow his words later on. But during those elections it was something that his Democratic colleague couldn't beat.
The controversial nature of the statement focuses the attention on this issue - at the expense of other issues. So Netanyahu could draw the attention away from the economy and inequality - where he is weak - to security issues where he is strong.
We see the same principle now also in the US. Except for Obamacare Obama has been very unsuccessful in reframing the public discussion. In his foreign policy he has been completely unable to get rid of the neocon influence with its absurd demand that the US should always stay the absolute ruler of the world. The end result may well be that one day the US may suddenly find itself in the same position as Britain: rotten at the core. In finance he has similarly failed to confront the "rulers of the universe". Only now, in his last two years, do we see some timid efforts to change the discourse.
On the left side of the political spectrum president Roosevelt is probably the person who did most to change the norms. It probably helped that he came from a wealthy establishment family. He didn't feel a revolutionary: he just did what needed to be done. In contrast we see in Obama someone who is in awe of the establishment and afraid that he will do something wrong. It is what made me have a preference for Romney in the last US presidential elections. He might be more conservative, but he looked also more of a man who would follow his own conscience than Obama.