Fall-Winter in Michigan....if you are going out to a jazzy spot....jeans with a v-neck sweater & tie is a cool look. If anyone saw CNN Black in America...sort of like what the guy was wearing after they came back from the commercials. A another example would be hip hop artist Common.
But that's exactly the issue, in the "Ivy League" look posted or with a v-neck sweater and tie or cardigan and tie, the tie isn't so obvious and so it looks okay. The same with Common, he does it, but almost always with a v-neck or a vest or something to cover up the tie. With a blazer, unless its very slim fit and very short cut, I just can't see it looking good.
The wash of the jeans (dark or black) and the type of tie (skinny to very skinny) are also crucial. This is a look that is hard to get right but very, very easy to get very wrong.