Since I mentioned banning the Joint List as a possible way for Netanyahu to "start rigging elections", here is one for Gantz to do the same: Mandatory voting.
If liberals in Tel Aviv and Arabs are forced to go to the polls under threat of fines that will raise their turnout, while it seems the right wing base (or at least the Haredi) will turn out no matter what; so mandatory voting should mean a left+Arabs majority.
Of course, mandatory voting is infinitely more democratic than banning the Joint list 
I don't really think much of mandatory voting as a policy. The right to vote should also come with the right not to vote.
Mandatory voting does not work too badly in Australia and there is nothing to force an unwilling voter not to spoil their ballot. You could also include an explicit none of the above option on the ballot.
Most of Latin America also has mandatory voting and politicians are hardly amazing in the region
