Washington (CNN) Amid the wall-to-wall coverage of Hurricane Irma and President Donald Trump's stunning debt ceiling deal with Democrats, you almost certainly never heard these two names: Charlie Dent and Dave Reichert.

And, chances are, if you are a semi-normal person who doesn't follow politics obsessively, you don't recognize either man's name.

But the retirement announcements of these two moderate Republican House members from competitive swing districts is, without question, the most important political development of the week -- with potentially long-lasting consequences on Washington.

Why? Because both men represent an increasing abandonment of the current GOP by politicians in the ideological middle -- or, as Dent put it in a statement released Thursday night announcing his retirement , the "governing wing" of the Republican Party.

(Note: Democrats don't have much of a "governing wing" left, either, after losses in 2010 and 2014.)

It's worth quoting from that Dent statement as some length. Here's the key part:

"As a member of the governing wing of the Republican Party, I've worked to instill stability, certainty and predictability in Washington. I've fought to fulfill the basic functions of government, like keeping the lights on and preventing default.

Regrettably, that has not been easy given the disruptive outside influences that profit from increased polarization and ideological rigidity that leads to dysfunction, disorder and chaos."

It's hard to imagine a Democrat writing a more frank indictment of the current state of the Republican Party than that.

What Dent is making clear -- without exactly saying it -- is that he no longer thought it was worth fighting against the forces of rigid orthodoxy that had overrun his party. That he didn't leave the GOP -- it left him.

"You know I expect a certain amount of dysfunction in government but those guys have taken the 'fun' out of dysfunction," Dent told CNN's Manu Raju in an interview Friday.

JUST WATCHED Dent on CNN before the 2016 election: I'm not voting for Trump or Clinton Replay More Videos ... MUST WATCH Dent on CNN before the 2016 election: I'm not voting for Trump or Clinton 05:44

The twin retirements of Dent and Reichert matter far more than in some esoteric debate about the current ideological state of the Republican party under Donald Trump. They both represent districts -- one centered in Allentown, Pennsylvania, the other in the Seattle suburbs -- that could well flip to Democrats in the pivotal 2018 election.

Reichert is one of 23 Republicans who represents a district Hillary Clinton carried in the 2016 presidential election. His 8th District was also won by Barack Obama in 2012. Dent's 15th District is slightly more friendly for Republicans; Trump won it by 7 points in 2016 but Mitt Romney carried it by less than 3 in 2012.

Dent and Reichert are the 13th and 14th House Republicans to announce their plans to leave office in 2018. Nearly half of them (six) are doing so without another obvious job in mind, according to The Washington Post's James Hohmann. Reichert is the second member to retire from a district Clinton won in 2016 ; Florida Rep. Ileana Ros-Lehtinen, another outspoken moderate, announced she would leave Congress earlier this year.

As "Inside Elections" analyst Nathan Gonzales noted in Roll Call earlier this week , there's almost certainly more retirements to come. He calculated that, on average, 22 members have retired without another job in each election since 1976.

The danger for Republicans is that Dent and Reichert (and Ros-Lehtinen) are the leading edge of a stampede of Republican moderates out of Congress. The Republican majority -- one of its largest in the last 100 years -- is built on its gains not only in the South over the past two decades but also surprising strength in the northeast corridor -- New Jersey through Maine. The vast majority of those members identify far more with Dent or Reichert ideologically than, say, Steve King of Iowa.

But the Republican president has governed -- this week excepted -- in a way far more likely to please King than Dent. And, increasingly, calls for party purity are forcing moderate Republicans into contested primaries. It seems more than a coincidence, for example, that Dent's retirement comes hard on the heels of state Rep. Justin Simmons' decision to primary the GOP incumbent . Simmons blasted Dent as more closely aligned with Democrats than Republicans.

And, as Dent noted in his retirement statement, an entire world of outside groups have grown up to foster and fuel and fund these ideological challengers, providing them with viability that they might not have had even a decade ago.

History suggests that the 2018 election is going to be a tough one for Republicans in Congress. Since 1946, when presidents are above 50% approval, their party loses an average of 14 seats in House in midterms, according to Gallup calculations . But, if a president is below that 50% approval -- and Trump is way below that -- the average seat loss is 36 seats.

Those are daunting numbers -- even without the possibility that Dent and Reichert are the leading edge of a series of retirement from members in swing districts due to increasing feelings of ideological isolation.

Dent, for his part, predicted a reckoning for his party

"I do believe that this year -- 2018 -- will be similar analogous to 1994, 2006 and 2010 where each of those years, each of those cycles, one party controlled all three branches of government," Dent told Manu. "So I do think it's analogous. So the party of the President, the party in control, will run into a head wind, and probably a stiff head wind, just a matter of how stiff. Will it be a gentle breeze or gale force wind? I don't know. But I think a lot of members here are going to have to plan for the worst and then hope for best."