The hardcore Cruzers alienated themselves. That’s why about 2 months ago Cruz and Trump support were about even, and now Trump is supported by around 80 percent of the forum today.
Many Cruz supporters were run off of this forum or became so disgusted they chose not to participate. The result is that the "caucus" to which you refer is now a tiny little echo chamber of about 200 Trump supporters. Do you see Trump getting 80% anywhere in the real world? He does not yet have a majority vote in any state, only pluralities. Most Republicans want someone else.