Obamacare has only gotten passing attention this election season, but it is likely to return as a hot topic early next year. That is because during the 2015 tax filing season, millions of low- to moderate-income taxpayers will likely first learn that they exceeded the income eligibility levels for the Obamacare subsidy they received in 2014 and will need to repay the government. This repayment could result in a sufficiently abrupt and targeted reduction in consumer spending that could delay the Federal Reserve from starting to raise short-term interest rates, which the consensus view expects to occur in March, coincidentally contemporaneous with when this looming "consumer cliff" hits.

President Barack Obama speaks during the Congressional Hispanic Caucus Institute Awards, Oct. 2, 2014, in Washington.

The Obama administration says 7.3 million Americans are participating in the Obamacare insurance exchanges and 87 percent, or 6.4 million people, are receiving some form of subsidy. This subsidy is not paid directly to them, but is paid by the government to the health insurers. The subsidy income eligibility levels depend on one's age and whether they have an individual or family plan, but are roughly $35,000 for younger individuals, $46,000 for older individuals, and $94,000 for a family of four.