A columnist for the Washington Post has warned Democrats not to be overconfident about the prospect of a wave election carrying them to control of Congress, suggesting most waves “break before they reach the shore.”

“Conditions look particularly good for taking back the House. Off-year elections in a president’s first term nearly always cost his party some seats, and President Trump’s historically low approval ratings are an especially heavy weight for Republicans,” wrote Karen Tumulty. “The fact that so many GOP incumbents are in a rush to retire is no mere coincidence.”

“So what could go wrong for Democrats in 2018? Plenty, actually.”

Despite public optimism from many Democrats, the party’s overwhelming lead in generic polling has evaporated following implementation of the tax bill and President Trump’s well-received State of the Union address.

“The spread is running at 6.5 percentage points in the RealClearPolitics average – just half where it was at the beginning of the year,” Tumulty noted.

A CNN poll released in January showed Democrats holding a five point lead over Republicans on a generic ballot, 49 percent to 44 percent – a significant improvement given Republicans trailed Democrats by 18 points in the same poll in December.

Likewise, a poll conducted by Monmouth University just before the SOTU address showed Democrats with a slim two point lead over Republicans, 47 percent to 45 percent.

“What should be more worrisome to Democrats — ironically enough — are some of the very forces that are working in their favor,” Tumulty added, citing the large number of Democratic candidates running in what could devolve into “large, messy primaries.”

In the case of Virginia’s 10th congressional district, Democrats worked hard to recruit popular state Senator Jennifer Wexton to challenge Republican Representative Barbara Comstock – widely considered one of the most vulnerable Republicans running for reelection as her Loudon and Manassas-based district gave Hillary Clinton a ten point margin of victory over President Trump.

Wexton now faces a contentious primary featuring eight candidates, and has fallen behind in fundraising to anti-human trafficking activist Allison Friedman, a darling of the far-left who only recently moved to the district.

“For an electoral wave to rise high enough to wash a majority-making two dozen House seats into the Democratic column, the party will have to take territory that Hillary Clinton could not,” Tumulty said, noting the wave election in Virginia last year cited by Democrats as a harbinger of the 2018 midterms was carried by Democrats winning in districts also won by Hillary Clinton.

Of the 15 seats won by Democrats in Virginia’s House of Delegates, 14 were in districts carried by Hillary Clinton, “suggesting that the party had done little to expand its reach since 2016.”

“Finally, perhaps the single biggest miscalculation that Democrats could make right now is to expect Trump to do all their work for them,” she concluded. “One thing to remember about waves. Most of them break before they reach the shore.”