Let me pose this question to you. Knowing that 300 million people live in the US, let's say that at least 40 million of those are fundamentalist Christians. They are among the most vocal group and have significant political power. They control most of the Republican party as we speak.
Do you honestly think that some idiot will announce one day in your lifetime, "Hey, you need this chip in your arm to buy and sell goods, if you don't then you will be sent to jail."
Do you have ANY idea how much of a STINK that would raise? Let me put it this way. Imagine, if you will, Obama passed another trillion dollar stimulus package, the courts ruled gay marriage was legal in every state, that anyone who believed in creationism had to be fired from a science position job, God was taken out of the pledge, and every public mention of the 10 commandments was removed. All this in one week, too.
The public outcry to the above would be nothing compared to how the outcry would be if Obama decided to institute the "chip to buy and sell" policy. Nothing.