WASHINGTON – Democrats hoping to block President Donald Trump's agenda by winning congressional majorities in the 2018 midterm elections have just received a stunning reality check.

A recent article by David Wasserman published at fivethirtyeight.com – not known for being friendly to Republicans – reports that even if the Democrats win every Senate race in states that Hillary Clinton won in the 2016 presidential election or that Donald Trump won by 3 percent or less, they will still lose five seats in the Senate.

If they win all the House seats in the same states, they will still fall short of a majority in that chamber of Congress as well.

"The GOP's current 52-seat majority makes the Senate look tantalizingly competitive," Wasserman wrote. "But a look at the map reveals that the Democrats hold far more seats on borrowed time than Republicans do. The GOP doesn't hold a single Senate seat in those 14 states that are more Democratic-leaning than the country overall. Meanwhile, Democrats hold six seats in the 26 more-Republican-than-average states, and all six are at risk in 2018."

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This news comes at a bad time for the Democrats: They have 25 seats up for re-election in the 2018 midterms, whereas the Republicans only have eight.

Ten Democrats are running in states that Trump won in 2016, and five – Sens. Joe Donnelly (Indiana), Heidi Heitkamp (North Dakota), Joe Manchin (West Virginia), Claire McCaskill (Missouri) and Jon Tester (Montana) – are in states that he won by more than 15 percentage points.

In fact, to attain a supermajority of 60 votes in the Senate, all the Republicans have to do is win the Senate races in the states Trump won in 2016.

There are only eight Republican seats opening in 2018. There are 17 seats open in states where Trump was victorious. Even if the Republicans lose Nevada, which Clinton won in 2016, they could still end up with 61 Senate seats in 2018 by winning Trump's states, which would give them to power to pass any legislation they wanted without the possibility of a Democratic filibuster.

Wasserman attributes this shift in senatorial demographics in part to the Democrats' increasing tendency to attract urban voters while the Republicans appeal to a more rural base. He points out that Democrats have recently increased their advantage in states like New York and California, both with huge populations concentrated in cities.

Republicans, on the other hand, are winning in the large swathe of the nation known as "fly-over country."

One look at the electoral map from 2016 shows the Democrats won the West Coast and the Northeastern states, while the vast middle of the country is almost entirely GOP, with the exception of traditional liberal strongholds such as Illinois and Colorado.

This gives the Republicans an edge in the number of states more sympathetic to their policies, and thus gives them the Senate and the presidency, even though they may not have a majority in a straight national popular vote.

Wasserman points out that it took a series of catastrophic events to bring about the Democrats' supermajority that led to the passage of Obamacare.

"What did it take for the party to be able to obtain 60 seats?" he asked. "The Iraq War, Hurricane Katrina and a stock market crash, which generated a huge backlash against President George W. Bush and Republicans in 2008. Today, it would take even more cataclysmic events under GOP rule to propel Democrats to a supermajority over the next six years.

"Meanwhile, all Republicans would need to obtain 60 seats would be to win every seat in the 30 states that Trump won," he continued. "No Clinton states needed. That's a plausible outcome over a few election cycles.

"The implications beyond Congress, especially for the Supreme Court, should deeply worry Democrats," Wasserman concluded. "Even if there's a Democrat in the White House in 2021, the Senate majority that is so critical to confirming his or her nominee could be much harder to come by than it has been in decades past."

Can the Republican Party save itself? Richard Viguerie has the prescription in "Takeover."