RENTON, Wash. -- Seattle Seahawks defensive end Michael Bennett says Colin Kaepernick remaining unsigned reflects the state of the NFL.

"I think the league is built on middle America, and most of the middle of America is predominantly a white crowd," Bennett said Wednesday. "That's just the truth of it. I think race is not something that the NFL wants to be a part of or get behind. But the league is predominantly African-American.

"So the issue that he's dealing with is what we're all dealing with. We all come from the inner city or we've been a part of communities where we felt like we've been judged because of the color of our skin or who we like or if a woman -- any issue to deal with. We've all been dealing with it with someone in our family."

Bennett wore an "I know my rights" T-shirt and hat, expressing support for a campaign started by Kaepernick. He said that he has spent time with Kaepernick this offseason and that almost everyone knows why the quarterback doesn't have a team yet.

"Obviously, there's the elephant in the room why Kaepernick isn't signed, and most people know why," Bennett said. "I've said this several times, and I'm not afraid to say it: I think race and politics in sports is something people don't want to hear about, nor do people want to be a part of."

The Seahawks were the only team that brought Kaepernick in for a free-agent visit, but they ultimately ended up passing on him. Seattle signed Austin Davis to compete with Trevone Boykin for the backup spot behind Russell Wilson.

"I don't know what factors into the Seahawks' not signing him," Bennett said. "I know the Seahawks were the only team that stepped up and gave him the opportunity to [visit]. So that says a lot about the organization."

Seahawks defensive end Michael Bennett says race and politics are the reasons that Colin Kaepernick is unsigned. Elaine Thompson/AP Photo

Coach Pete Carroll said the Seahawks didn't sign Kaepernick because he believes Kaepernick is a starting quarterback, and Seattle already has a starter in Wilson.

"If he feels that this is not the right situation because we have a starting quarterback, then that's his choice," Bennett said. "I think he's able to have that choice because he's shown that he's of a winning pedigree. He wants to make sure he doesn't have that competition behind his quarterback. I think it's justifiable."

Bennett also revealed Wednesday that he has been writing a book, titled "Things That Make White People Uncomfortable."

"I think the title is just a title to start a conversation so people want to read it," Bennett said. "The book I'm focusing on is issues that I see that are important in America, and they are my views and opinion.

"This is my story, my journey, my thoughts on sports, my thoughts on issues in America, my thoughts on women's equality, different issues like that."

Bennett said he has drawn inspiration from Kareem Abdul-Jabbar and is getting help with the book from author Dave Zirin. He has been working on the book for the past five or six months and said it should be released in December or January.