American politics over the last 25 years or so seems as if it's a roller coaster of sudden and unpredictable plot twists, each more improbable than the last: the ascension of a Republican majority in Congress for the first time in four decades; the impeachment of a sitting president; a national election decided by the idiosyncratic design of punch-card ballots in a single Florida county; a coordinated series of major terrorist attacks on American soil; two long and unresolved wars; a catastrophic economic crisis; the election of the first black president in history—followed immediately by the election of Donald Trump to the same office. The fortunes of the two parties have appeared to reverse with whiplash-inducing rapidity multiple times over this period, with neither side managing to establish an enduring hold over the affections of an impatient and dissatisfied electorate.
Pull back to a wide-angle shot, though, and our current political climate actually exhibits considerable stability. The following regularities (I don't view them as "rules," which would imply assuming an indefinite permanent validity) have largely held across the entire period from 1994 to the present, and certainly since 2000 or so:
1. The two parties are closely matched at the national level in both presidential and congressional elections.
2. The vast majority of voters are consistently loyal to a single party in both presidential and congressional voting.
3. Most individual states and congressional districts are securely and predictably Democratic or Republican in national elections.
4. However, because of #1 above, a national "wave" in favor of a single party can easily reverse control of the presidency or either house of Congress, flipping pivotal swing states and districts from Democratic to Republican (or vice versa) and even producing scattered upsets in normally safe partisan strongholds elsewhere in the nation.
5. These "waves" commonly form as a backlash against unified control of the federal government by the party in power, which tends to simultaneously alienate swing voters and disproportionately mobilize angry members of the opposition party to show up at the polls or to run for office themselves.
6. Many citizens treat their congressional vote as a referendum on the national parties and party leaders, rather than as a choice between the personal attributes of the individual candidates on the ballot.
With these six regularities in mind, let's turn to the results of Tuesday night's special election in Kansas. This was a "deep red" congressional district—by any metric, one of the 100 most Republican seats in the country—and, as we might expect, the Republican candidate won (see #2 and #3 above). However, the margin of victory was only about 7 percentage points, even though the Republican nominee was a statewide elected official while the Democrat was a political unknown who was outspent and out-organized (see #6). The closeness of the result suggests that the electoral climate has worsened considerably for Republican candidates since last November, in large part due to the disastrous first weeks of the Trump presidency (see #5 and #6).
If we compare the Kansas results to the previous general election, they appear to represent a dramatic shift in the political order over just a few short months. But if we place them in a wider context, they seem much less surprising—if anything, somewhat predictable. Even the political professionals at the Democratic National Committee and Democratic Congressional Campaign Committee fell prey to this ultra-short-term thinking, dismissing the electoral chances of their party's congressional nominee based on the results of the 2016 election and its immediate predecessors, and thus failing to invest the organizational and financial resources in Kansas that might have made the outcome closer still.
Should they—or we—really have been all that surprised? By every conceivable indication, the Trump presidency is poised to be a massive electoral albatross for Republican candidates from coast to coast—and there is, at this stage, little reason for the party to hope that he will rectify his governing problems in time for next year's midterm elections. Whether or not Republicans actually cede control of the House in 2018 (see #1 and #4), it is near-certain that they will lose a substantial number of seats unless a major rebound occurs in the president's perceived job performance. But let's not be shocked—a newly successful congressional Democratic Party would not be a sudden departure from the patterns of recent history. Rather, it would be yet another regular occurrence in our predictable political age.