The Israeli Electoral System makes polling very risky. That's because you vote for a political party, and its list of potential Knesset Members. The head of the party which, post-elections, can form a coalition becomes Prime Minister. That's one of the reasons why in recent elections many more people end up voting Likud than voting for the party they had indicated for the poll, if asked.
You may like the ideology/platform of a certain party, but its leader seems totally incompetent as potential Prime Minister. So, a certain percentage of voters find themselves taking the Likud ballot, even though it's not their prefered party.
|Here I am voting in the 2015 Knesset Elections|
A poll, like this, showing thirty 30 seats, out of the one hundred and twenty 120, for Likud means that only one quarter, 25% of the voters are thinking of voting Likud. But in that very same poll, you see that 39% of those polls see Netanyahu as "most suited to be Prime Minister," and his runner-up is "34% Don’t know/Other."
And please don't claim that "voting districts" will make the system easier. That would be a totally hellish nightmare. Have you ever heard of GERRYMANDERING?