It's not really a surprise to be honest. When a people are pushed to breaking point, they will elect the extremist party.
It happened in Germany in 1933. With the aftereffects of the Great Depression still being felt, the German people were out of work, desperate, and the weak government was seen as ineffective. The Nazi Party promised to put people back to work, and to rip up the very unpopular 'Treaty of Versailles'...in particular the 'War Guilt Clause' in which Germany had to accept the sole blame for starting the war (which as any historian will tell you, is not true!). So, the Nazi's were voted in with 35% of the vote, making them the largest party in Germany...and from there they conslidated their power, making them the single largest party in Germany. At that point, they set about destroying democracy from within.
What we have here is a similar situation. The Middle Eastern situation is a mess, there's too much hate, on both sides. But clearly, the Palestinian people feel oppressed, and they see the current government as weak. Hence, they vote in the extremist party...and while it's too early to say where it might lead, when the people effectively swing their support behind 'terrorists', then you know that things aren't starting to look good.