I have many things to say about this. Let me begin with providing background information about the incidents at Cornell College (although I imagine that OP is familiar with them as well, as I can't think of any reason that an individual who is not affiliated with Cornell would be on a college student's twitter account).
At Cornell, there are two legal graffiti spots: a large rock by the oldest building on campus and the "kiosk", which is three metal pillars outside of the student center. On Sunday night/Monday morning, an "unaffiliated representative" (their words) wrote the worlds "build a wall/build it tall" on the kiosk. When the administration did not respond, students (including the student-founded Latino organization) repainted the kiosk to read "Wall or no wall, we stand tall/land of immigrants" at around 11 am. The Cornell administration did not respond to the words painted on the kiosk until 8 pm when they sent out an email essentially skirting around the issue, passing it off as freedom of speech and saying that the minorities on campus FELT marginalized instead of recognizing that they ARE marginalized. This is when Martinez decided to run unattached and made the Facebook post that the OP shared. On Tuesday night, members of the Latino organization were off-campus at a nearby pizza joint/gas station (in true small town Iowa fashion) when members of the football team driving in a car started verbally harassing them, repeatedly yelling "build a wall". The police were then called and the football players admitted to being drunk (remember they were driving) and said that it was all a joke. However, the football players were let off with a warning. The administration began investigating the issue further and sent out a second email claiming that events like this will not be tolerated. On Wednesday night, a "vigil for peace" was held and was attended by many faculty members. Later Wednesday night, students wrote "Trump 2016" in chalk across campus and the Latino organization responded by changing most/all messages to "Love trumps hate 2016" or other similar messages. This has not be addressed by the administration as of the time of this post.
Sanjuanita Martinez is a strong, intelligent, talented, passionate individual who happens to be Latina. She earned her place at Cornell and has excelled both in academics and on the track. Anyone who knows Sam knows that she stands up for what she believes in and doesn't back down. She genuinely believes in this issue. She wouldn't be putting her chance of getting another All-American award (or a potential win) in jeopardy if she didn't. This is about more than the racially-charged messages. This is about the safety of minorities in this country. This is about the small microaggressions that occur every day in every place (yes, even at Grinnell and Beloit). This is about the apathy and institutional racism that the Cornell administration initially displayed towards the issues that affected and continues to affect so many of its students. This is about making Cornell and our nation as a whole a better place.