In short, these eighty members represent an America where the population is getting whiter, where there are few major cities, where Obama lost the last election in a landslide, and where the Republican Party is becoming more dominant and more popular. Meanwhile, in national politics, each of these trends is actually reversed.
In one sense, these eighty members are acting rationally. They seem to be pushing policies that are representative of what their constituents back home want. But even within the broader Republican Party, they represent a minority view, at least at the level of tactics (almost all Republicans want to defund Obamacare, even if they disagree about using the issue to threaten a government shutdown).
In previous eras, ideologically extreme minorities could be controlled by party leadership. What’s new about the current House of Representatives is that party discipline has broken down on the Republican side. On the most important policy questions, ones that most affect the national brand of the party, Boehner has lost his ability to control his caucus, and an ideological faction, aided by outside interest groups, can now set the national agenda.
Through redistricting, Republicans have built themselves a perhaps unbreakable majority in the House. But it has come at a cost of both party discipline and national popularity. Nowadays, a Sunday-school teacher can defeat the will of the Speaker of the House.
Dysfunction in Washington is now structural in nature. Gerrymandered House districts electing more extreme partisans unwilling to compromise, a Senate that requires 60 votes to accomplish anything substantive, and the loss of earmarks as a tool to enforce party discipline leads to a Congress incapable of acting. Under these circumstances, it’s only to be expected that the current Congress is one of the least productive in recent memory, or that we’re now a mere days away from a government shutdown, and have a non-trivial chance of defaulting on US debt in about a month.