Rubio and Cruz need to continue to relentlessly pound Trump from every direction. Their campaigns should be sharing information and working together in their effort to take down Trump. There's another nuclear bomb they can drop on him that I haven't seen them use yet. (But maybe I missed it. I don't know.) Gather together some of Trump's derogatory comments about women, and bring them up during the next debate. Give example after example of Trump's vulgar comments (boasting about committing adultery with so many women, talking to Howard Stern about trying to avoid getting STDs from the women he has sex with, women he refers to in such a derogatory way, etc.). There's a lot of that sort of material circulating, and some of it comes from videos of Trump, his own books, etc. Put together a collection of descriptions of that material and quotations of it, drop it on his head in the middle of the next debate, and watch him explode. Drive a wedge between Trump and half the voters (women). Ask the audience if they want a president who's so abusive of women. Ask them if they want to face Hillary Clinton and the charge of a Republican war on women with somebody like Trump representing the party. Then close with Rubio's line about how the party of Lincoln and Reagan must not become the party of Trump. Or use whatever better line they can come up with. This should be done by both Rubio and Cruz. Don't just do it once. Hit him from both sides.
Do this on other issues as well. Pound Trump relentlessly. And make some cryptic comments about how there's more where that came from. Get Trump paranoid and looking over his shoulder.
Rubio and Cruz can't hold back, and they can't wait. Do it now, do it forcefully, and do it relentlessly.
If any of you have any contacts with the Rubio and Cruz campaigns, please pass on this sort of suggestion. I would think they're aware of the possibility of using Trump's comments on women against him, but I haven't noticed them doing it yet. It's important that they not pass this opportunity by. Encourage them to act on it.