President Barack Obama isn't talking about it. Neither is Mitt Romney. But come January, 163 million workers will feel a big tax bite regardless of who wins the election.

A temporary, two-year reduction in Social Security taxes expires, and good luck finding anyone in Washington who wants to extend it.

Neither Obama nor Romney has proposed renewing it, and lawmakers in both parties are down on the idea. Even Republicans who have sworn off tax increases have little appetite to prevent this one. Powerful advocates for seniors, like AARP, oppose an extension.

For a typical worker making $50,000 a year, it will mean a paycheck that is about $83 smaller each month. Six-figure, two-earner families will pay as much as $4,500 more in Social Security taxes next year.