GREEN WAVE: Democratic cash swamps House Republicans.

More than 40 House Republican incumbents were outraised in the final quarter of 2017 by one — or several — of their Democratic opponents, according to the latest round of fundraising numbers. And of that group, more than a dozen had less cash on hand than their Democratic challengers.

For the GOP, here’s the really disturbing part: The trendline is getting worse, not better. Despite the myriad advantages of incumbency and control of Congress, there are more House members with less cash on hand than their Democratic challengers than the quarter before.

“Those numbers should be concerning for all Republicans,” said Mike DuHaime, a GOP consultant based in New Jersey. “This is going to be the most challenging political environment since 2006, so you have to be ready. And lot of these members came in after 2006, so for many, this will be the most challenging environment they’ve ever run in. And that’s going to prove difficult.”

A flood of Democratic money poured into House races across the country in 2017, provided in large part by small-dollar, online contributors animated by opposition to President Donald Trump and the Republican majorities in Congress. More than 80 Democratic challengers in Republican-held districts have at least $250,000 in cash on hand at the end of the year — a sign that the House battlefield may be wider than previously thought.

I’m getting the feeling that this is going to be a long, hard slog.