“I don’t see how the Democrats do it,” said Larry Sabato, director of the University of Virginia’s Center for Politics. “If they’re lucky they’ll get [a] double-digits [gain] … The most likely outcome is Democrats pick up single-digits.”

The independent Rothenberg Political Report says the most probable scenario is for Democrats to pick up seats in the single-digit range, though it adds that anything from a Republican gain of one seat to a Democratic pickup of six is possible.

House Editor David Wasserman of the independent Cook Political Report agrees a Democratic gain in the low-to-mid single digits is most likely.

“There’s just no wind blowing in either direction, that’s very consistent,” he said.