President Barack Obama's insistence on higher taxes for top earners and Republicans' refusal to raise rates leaves negotiators with arithmetically complex and politically fraught choices.

Tax questions will be central today when Obama holds his first face-to-face conversation with House Speaker John Boehner since the Nov. 6 election. At the White House meeting on the so-called fiscal cliff, Obama also will host House Minority Leader Nancy Pelosi, a California Democrat, Senate Majority Leader Harry Reid, a Nevada Democrat, and Senate Minority Leader Mitch McConnell, a Kentucky Republican.

As they try to find a solution both sides can accept, some moves that ease the math complicate the politics. Republicans oppose higher rates while limits on tax breaks generate opposition from interest groups that rely on them, including nonprofit organizations, the home-building industry and residents of high-tax states.