Congratulations, Republicans. You just gave Democrats the Senate.

Yesterday Republicans succeeded, finally, in passing a tax "reform" abomination that is deeply, widely, and rightly reviled. As they were hastily and dutifully completing the task of selling out middle and working class Americans to give their donors cash for that critical third yacht, three new polls were released showing Republicans 12, 15, and 18 points down to Democrats in next year's race for the House of Representatives, numbers that would make it all but impossible for Republicans to preserve their majority in the chamber.

At this point, smart gamblers are probably putting big, beautiful stacks of chips on the Democrats. Conservative analyst Sean Trende of RealClearPolitics, a man not known for hyperbole, tweeted that he expects as many as 40 seats to light up blue (Democrats only need 24), if not more. Public Policy Polling has been testing individual House contests this fall, and without even sniffing around all of the expected battleground races, found 25 where the Republican trails a generic or specific Democrat, with many more once-impregnable fortress districts that are crazy close. And Republicans, already weary from a schedule of mindlessly serving their well-heeled overlords, have another 11 months of frenzied lunacy from the most unhinged White House in American history to get through and a 2018 legislative agenda that could charitably be called empty and unpromising.

These catastrophic numbers are all but certain to get worse by November 2018. For Republicans hopeful that people will warm to the very modest and very temporary tax relief that will be enjoyed by some, though not all, non-Richistanis, there is a small problem: 2018 taxes won't be filed until 5 months after the midterm elections, and people are unlikely to forgive the GOP its many treacherous trespasses this year because they found an extra 18 bucks in their weekly paycheck. And if they continue on this trajectory of achieving virtually nothing except torpedoing insurance markets and gift-wrapping tax goodies for real estate speculators, Republicans might hand the Democrats a filibuster-proof Senate majority over the next two cycles.

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Just a few months ago, the 2018 Senate map looked apocalyptic for Democrats. The party must defend 25 seats next year (26 if Al Franken goes through with his resignation), with a whopping 10 of them in states won by President Trump, several by blowout margins. Republicans entered 2017 with a not-unreasonable confidence that they might buck historical trends and expand their majority in 2018. But after a year of non-stop scandal, ugly political chaos, and declining public faith in the party and its inept leadership, everything looks different. Republicans now risk losing the Senate, and not necessarily just by a single seat. And if this partisan environment persists, they might deliver a filibuster-proof Senate majority to a unified government of vengeful Democrats in 2020.

Can this really be? If data from elections in 2017 is any indication, yes. The average swing from 2016 across the seven special elections for the House and Senate over the past year has been 16 points toward team blue. It was an expression of broad disgust with the performance of the president and the Republican Party across a very diverse set of races.

What would a 16-point swing mean for next year's Senate elections if those numbers held up for Democrats? Most obviously, Nevada's hapless senior senator, Republican Dean Heller, is history. That kind of wave will also make it very difficult for any Republican in Arizona to hold retiring Sen. Jeff Flake's seat. Combined with the shock victory of Democrat Doug Jones over Roy Moore in Alabama last week, those two pickups would be enough to flip the Senate if Democrats win all of their toughest races.

But this Republican carnage might not stop at narrowly tossing away their majority. Do you know who else is endangered by a 16-point swing against the Republican Party? Ted Cruz. The junior senator from Texas won his last race in 2012 by just over 16 points in a state that is gradually but unmistakably being transformed into a battleground. A June 2017 poll put his approval rating at just 38 percent. President Trump carried Texas by fewer than 10 points, and the Democrats have a superb recruit in Congressman Beto O'Rourke. Similarly, the Tennessee seat held by retiring Republican Bob Corker is now very much in jeopardy. While Corker won his last race by 34 points, it was against a total lunatic who rightly lacked any party support whatsoever.

Wave elections also sometimes unexpectedly endanger what were presumed to be seats so safe you could leave their front doors wide open. This is how Republican Mark Kirk captured a ticket to D.C. out of Illinois in 2010. A 16-point swing against the Republican Party also puts people like Roger Wicker (Miss.) and Deb Fischer (Neb.) in peril. At minimum, if the polling looks this bad for the GOP by mid-summer, Republicans are going to have to use scarce resources defending seats they never thought in a million years would be in play. And Democrats who would be vulnerable in just about any other election year, like Heidi Heitkamp (N.D.) and Joe Donnelly (Ind.), may very well survive.

If Democrats pick up four seats instead of just two next November, they will also set themselves up for a historic victory in 2020, when they could conceivably win a filibuster-proof majority of 60 or more. If you think that's impossible, you're not looking closely enough at the map, which is almost a mirror-image of the challenging one facing Democrats next year; 21 Republican seats will be up against just 11 for the Dems, and the only Democratic seat that looks dicey right now is Jones in Alabama.

Meanwhile, Republicans would face difficult races in Colorado, Georgia, Maine, and North Carolina even under toss-up partisan conditions. If things are this grim three years from now, they could pretty easily cough up all four of those seats (with special thanks to Susan Collins destroying her reputation by voting for the tax bill), leaving Democrats just three short of being able to do whatever they damn well please in Congress. Those three pick-ups could come from many different places, depending on retirements.

Can Republicans avoid this fate? For sure, a lot can happen in three years. But Republicans are being pulled inexorably into the deep by two anchors: One is, of course, their bleeping moron of a president, a man who hasn't learned a single thing in nearly a year on the job, routinely sends the entire party careening off message with some needless provocation, appears to own a million shares in the stock market price of being a jerk, and is probably even money to be accused by Special Counsel Robert Mueller of obstructing justice.

But even if the president was a generic Republican with properly-tailored suits who stopped drinking Diet Coke and rage-tweeting sometime before midnight, the party would still be reeling. That's because the Republican policy agenda is Superfund-cleanup-site toxic. Even trace amounts could kill an elephant. The party is bleeding out millennials like they ruptured a political artery. Huge majorities of the American people see through the blizzard of B.S. and bad faith the GOP is using to press its inane policies, and they realize that the party is basically operating a Make a Wish Foundation for perfectly healthy rich trust funders.

That's a recipe for electoral disaster, and unless Republicans sharply and suddenly change course, they will richly deserve it.