Why do you think Trump has abstained from attacking Rubio?

[Ronnie]

I find it pretty striking that, in debates and interviews, Trump always resists taking on Marco.  Earlier in the campaign, he called him a lightweight and mocked him for the water incident in his response to the SoTU, but that's it, really.

Could he be on Trump's running mate shortlist?

[eric82oslo]

- Doesn't have anything personal against him (like he has with Bush)
- Hasn't been directly attacked by him (like he has by Jindal, Graham, Rand Paul, Perry, Kasich, Cruz & Bush)
- Sees him as weak / inexperienced perhaps
- Knows that he is very well-liked by the grassroot base just like Carson & Cruz
- Perhaps envisions him as a potential VP choice, especially since he's so young, from a crucial  battleground state and speaks Spanish fluently
- Sees him as the most handsome presidential candidate running this year (looks obviously means a lot to Trump, and we've seen proof of over and over and over again)
- And perhaps the most obvious one: Doesn't currently see him as a major threat (unlike Cruz & even Bush, because of his money, experience, establishment support, influential family and powerful friends)

[MIKESOWELL]

Marco Rubio is a political lightweight who was temporarily given media steroids due to his strong third place showing in Iowa. He might be on Donald Trump's shortlist for the veep slot, but I think he hasn't really attacked Rubio recently because he most likely recognizes Rubio's considerable, but mostly regional appeal. He's inexperienced and is tailor made for the second spot.

[Fmr. Pres. Duke]

He probably thinks he's weak and not worth going after. I can't really figure out why else he's abstained from attacking him. I doubt he's on his short list for VP - that would be a surprising pick.

[PeteB]

I find it pretty striking that, in debates and interviews, Trump always resists taking on Marco.  Earlier in the campaign, he called him a lightweight and mocked him for the water incident in his response to the SoTU, but that's it, really.

Could he be on Trump's running mate shortlist?

Three reasons, two are strategic and one is personal:

1. Rubio taps into a lot of Cruz voters - it doesn't make sense for #1 to go after #3, when that person is cutting #2 to size!

2. Unlike Cruz, Rubio comes across as a nice (and inexperienced) person. There is very little for Trump to gain PR-wise in going after him (unlike Cruz o Bush)

3. Very simply - Rubio did not attack Trump personally!

[Beezer]

Trump loves tic tacs