The Israeli system empowers them. They each can bring down the government and they each and every one have a different electorate they are beholden to. Prime is not all powerful, just has the first say on some things. But can be undermined by others and made a fool of. Yishai went to the US because the US is beginning to understand that no matter his intent Netanyahu speaks only for himself and a limited few others. God Save the UK if this becomes their system.
U.S. says it killed 10 AQAP Islamist militants in four air strikes in Yemen since April 23 (Reuters)
from the article: Barak: Ministers' provocations over Jerusalem harming Israel's interests