[The Right wing Infidel]

http://trailblazersblog.dallasnews.com/2015/10/white-house-press-secretary-teases-ted-cruz-on-canadian-birth-mlb-playoffs.html/

The democrats have already started using this to attack Cruz so Trump is 100% right that this will be used to slander and attack Cruz

[The Right wing Infidel]

http://www.foxnews.com/politics/2015/10/16/dems-make-jabs-at-ted-cruz-canadian-heritage.html

More , Trump is warning him that this is a issue he must confront and not ignore , Hillary will be relentless using this against them in the primary

[DoodleDawg]

The democrats have already started using this to attack Cruz so Trump is 100% right that this will be used to slander and attack Cruz.

If you want to call that an attack. But even if that's what it was meant as they're still late to the game. Trump was questioning Cruz's eligibility back in March of 2015 and before: Link