I think it's a mix of race and "my team" mentality where people are sold the same damn thing, but because their candidate said it, it must somehow be different or better.
This.
People will usually follow who they trust over those they don't. Sadly, when it comes to politics, that initial trust is usually dependent upon the letter D or R, or perhaps upon one issue someone finds most important, say gun control. Then when said person finds a candidate or political commentator who shares those same views on gun control, that person will subconsciously align the rest of his or her views to match those of the trusted candidate or commentator.
Ask the average American what their views are on one political issue, and you will very likely be able to guess their views on another completely unrelated political issue. It's the herd mentality.
I remember on this forum a while back, a member came out in favor of campaign finance reform to limit the influence of money on politics, and then literally within a month or two came out against it because of what Ted Cruz had said.
Sometimes I think people are just afraid to think for themselves. Or unable?