SANTA CLARA, Calif. -- It has been about 14 months since Nate Boyer and Colin Kaepernick met in San Diego to discuss Kaepernick's protest of racial inequality during the national anthem. Much has changed in the time since.

For Boyer, those changes have led to a series of events that left him penning a second open letter addressed to everyone in America and dealing with harsh feedback from all sides, including his brothers in arms.

Among the changes: The country elected a new president, Kaepernick is out of a job and bringing a suit against the NFL alleging collusion, protests during the national anthem have expanded, and Donald Trump has strongly voiced his disapproval of those protests, going so far as to call players who kneel "sons of bitches."

Open Letter To America Nate Boyer, a former NFL player and Army Green Beret who was with Colin Kaepernick on kneeling at the start, calls for unity on behalf of America. Read more

Watching it all unfold, Boyer, a former Army Green Beret and NFL long-snapper, has found himself frustrated by what he has seen. Something new popped up seemingly every week until Boyer finally reached his limit when he saw Eminem's freestyle rap video lashing out at Trump. In the video, the Detroit rapper makes a point of drawing a line in the sand, something Boyer references in his most recent open letter.

"Honestly, the thing that pushed me over the edge -- and I'm not knocking on Eminem -- it was that song, though," Boyer said. "It's kind of what I hinted at in the letter. We need less lines in the sand, and literally in that rap, he's saying, 'I'm drawing a line in the sand. You're either with me or against me. You're either for or against.' All these things I said in the letter, he said in that song. I understand the anger. I understand the frustration. I understand being upset with the remarks that President Trump has said because those also can be viewed as divisive. In my opinion, that's not the way to defeat that. It's not the way to beat it."

Boyer points to leaders such as Martin Luther King Jr. and Mahatma Gandhi as the model for the type of leadership that is most effective. The way Boyer sees it, King and Gandhi had their struggles, but they emphasized peace, love and acceptance. When challenged, they stuck to their beliefs and dealt with the fallout, but they were always pushing for change via peaceful means.

Colin Kaepernick and Nate Boyer have not spoken with each other since Super Bowl LI in Houston. Michael Zagaris/Getty Images

"That song is what really kicked me in the ass and made me feel like nothing I'm doing is working, and also I see what was happening all over the league, with more people kneeling, and they're kneeling in protest of something that the president said," Boyer said. "I was thinking, like, 'Man, what have I done?'"

To be sure, it's more than a song that led Boyer to again feel the need to speak up. From the moment Boyer got involved with Kaepernick and his protest, the messages have poured in.

Boyer has been inundated with responses from all parties, including on Oct. 13, when he published a second open letter to Kaepernick, President Donald Trump and all the American people via ESPN.com.

Much like many other parts of the protests, Boyer's role has become muddled, and that was another reason he felt the need to address the topic in a public forum. According to Boyer, some of Kaepernick's supporters have accused Boyer of going back on his original intent to understand and support the former 49ers quarterback.

Conversely, Boyer hears from those who believe he was the one who encouraged Kaepernick to protest in the first place, rather than that he offered an alternative for Kaepernick until he was ready to stand again. Boyer has always maintained that he wanted Kaepernick (and everyone, for that matter) to stand for the anthem, but he hoped they would do it because they wanted to.

Still, Boyer finds himself the target of hate, even from fellow Green Berets and other military veterans. In a couple recent chats, Boyer relayed two of the messages he has received.

The first, from a veteran who is not a Green Beret: "I just want to extend a personal f--- you, Nate. You're a disgusting disgrace to my uniform that you don't even deserve to wear. Do society a favor and go f---ing kill yourself."

Another, from a fellow Green Beret, in part: "I'm disgusted when I see a fellow [special forces] brother say he's more pissed at our president for calling players sons of bitches than he is seeing these scumbag player[s] kneel for the anthem. I'm disgusted when I see you with your head so far up Michael Bennett's ass, you can see what the hell he ate for dinner."

Such messages are disheartening to Boyer when they come from those who have also served this country.

"It bothers me a lot," Boyer said. "I care a lot what my community thinks, the special forces. I do care, but at the same time, I am truly trying to do the SF mission, which is be a warrior diplomat. You fight for something, but sometimes you're fighting alongside people who you might disagree with. You're trying to do the greatest amount of good for the greatest amount of people. We don't go to combat just to impose our will and force everyone into something. That's not what the Green Berets do. I don't know if some of us have forgotten that or whatever, but I have literally had a small percentage of special forces where I'm branded a traitor or someone that disrespects the flag."

In the latest letter, he proposed a meeting between Kaepernick and Trump in hopes that dialogue might end some of the hateful rhetoric Boyer has grown accustomed to.

Colin Kaepernick decided to kneel during the national anthem, rather than stand or sit, after a lengthy discussion with former Green Beret and Seattle Seahawks long-snapper Nate Boyer. Chris Carlson/AP Photo

Boyer and Kaepernick haven't spoken since the Super Bowl, though Boyer said he would like to talk to Kaepernick and, barring that, would like to see Kaepernick begin to speak publicly again. Boyer said he hasn't heard from anyone in Trump's camp but has talked to people on both sides of the issue who agree with his message of unity. Along the way, Boyer has sensed a frustration similar to his own, especially from people in the group a friend of his recently dubbed the "alt-middle."

"I don't control that," Boyer said. "All I did was sit down with [Kaepernick] for two hours 14 months ago, and for people to spin things so out of control and make so many assumptions about my involvement in this thing, there's so many guys in the special forces and these stupid Facebook groups that just crucify me. They just don't know.

"You reach a point of what are we doing here? Why can't we just all be together on this?"

Despite all that has happened, Boyer is sure to point out that the response to his latest words hasn't been all bad. In fact, most of it has been good. He just can't help but focus on the smaller percentage spewing negativity in his direction.

"[It has been] a ton of good," Boyer said. "Way more good than bad, way more positive. I'd say 90 percent positive in people reaching out, and I appreciate that. But I'm a glass-half-empty kind of guy, and I'm always going to do everything I can to fill the glass up. I'm not going to be satisfied. I want everybody to understand. I want everybody to accept the differences from both sides."