One party is winning, the other one not so much

In Obama’s first year in office, buoyed by the biggest presidential election victory since 1988, the Democrats expanded their House majority to 257-178; in the Senate, they could count a filibuster-proof majority for the first time since the Jimmy Carter era.

As a result, their numbers were robust enough to muscle through virtually all of Obama’s early agenda, most notably his health-care overhaul.

They lost control, however, in the devastating midterm election of 2010, which was fueled in large part by a backlash against the health-care law and government bailouts of Wall Street and industry. Democrats’ numbers further eroded in 2014.

Democrats’ hopes of regaining the Senate were dashed on Tuesday, when Trump’s victory provided a badly needed updraft for a handful of endangered GOP incumbents.

The lesson: Without Obama himself on the ballot, his army of young and minority voters would not show up in numbers needed to keep his party afloat.

Unlike Franklin Roosevelt’s durable New Deal coalition, the impressive political operation that Obama built does not appear transferrable to other Democrats — and therefore, may not live on past his presidency.