Both sides need a rude awakening about what is happening.
Trump is a protectionist and Cruz and Rubio are not. So they attack each other as liars instead of attacking the costly schemes of Donald Trump.
Trump will say anything, often pivoting on positions within sentences in a single speech. So Cruz and Rubio are attacking each other as liars.
Trump gleefully talks about beating up protestors as his rallies and sends out his online horde to attack those who do not like him while Cruz and Rubio, whose families fled from this sort of stuff, attack each other.