If history is any judge, Republicans should lose control of Congress or the White House during one of the five elections to come between now and 2015. Since Democrats and Republicans became national competitors in 1855, unified party control has lasted on average just 5.9 years. Unified Republican control has endured a bit longer, averaging 6.3 years. Even at its longest (with the onset of the 1896 realignment), Republican control of government has lasted just fourteen years. With the current Republican regime emerging from the elections of 2000, Republican control of Congress and the White House should have run its course by the elections of 2014.

The received wisdom, of course, is more often likely to predict Republicans' electoral invulnerability, and for good reasons. First, transformation of the South from solid “blue” to “red” is said to have created a substantial base for the Republican Party in both congressional and presidential elections. Second, population movement to the south and west, as well as GOP capture of numerous state legislatures in the South, has made redistricting following the decennial census (and in Texas in the intervening years) an effective tool for securing Republican seats in the House. Third, the decline of ticket-splitting districts (in which voters choose the presidential candidate of one party and the congressional candidate of the other) has narrowed Democratic opportunities for regaining control of the House. Only eighteen congressional districts won by John Kerry in 2004 are represented in the House by Republicans, compared to the 41 Bush districts held by Democrats.¹

The decline of competitive races nationwide, coupled with the Republicans' structural advantage in elections, certainly makes it hard for Democrats to regain control of the House.² Nor is the Senate within easy reach of Democrats, with the losses the party experienced across the South and elsewhere in the 2004 elections.

That is what the received wisdom might predict about the next ten years. I predict that Republican government is unlikely to endure uninterrupted over the decade. Despite the decline of competitive House races, the politics of slim electoral and legislative majorities will be the Republicans' undoing. Consider this alternative perspective on the nation's electoral future.

Congressional Republicans have won consistent, but small, majorities since gaining control of the House in the 1994 midterm elections. Republican majorities have held on average just over 50 percent of the chamber seats. In contrast, Democratic majorities in the previous decade held nearly 60 percent of the House. Nor were extra-large Democratic majorities an anomaly of the 1980s. Between 1954 and 1994, Democratic majorities in the House averaged exactly 60 percent of chamber seats. Given the magic number of 218 votes to prevail on a House vote, slim Republican majorities (averaging just 227 seats) have often left the GOP scrambling to build a majority. In contrast, over their 40 years of House control, Democrats held on average 261 seats, giving Democrats a typical surplus of 43 votes. Although the 2004 elections ushered in the largest GOP House majority since 1994, at 232 seats, the smallest Democratic majority over the past half-century (after the 1954 elections) was also 232 seats. Nor have recent Senate Republican majorities had many votes to spare, especially given that chamber's supermajority rules for ending debate. Since 1994, Senate GOP majorities have averaged just 53 seats, well short of the 60 votes needed to maintain a filibuster-proof majority.³

Down the Avenue, the Republicans' presidential margins have also been exceedingly narrow. In 2004 Bush won 51.4 percent of the two-party vote, up from 49.7 percent in 2000. Only three states switched sides in the two elections: two states with narrow Democratic wins in 2000 went Republican in 2004, and one state narrowly won by Republicans in 2000 voted Democratic in 2004.⁴

Given the distribution of the vote across the states, analysts of recent elections conclude that neither party has an electoral base sufficient to guarantee victory in 2008, and short-term forces could easily swing the election to either party. Moreover, when the president's party has controlled the White House for two or more terms, the incumbent party more often loses than wins in the following election—making 2008 a “time for a change” election.⁵ Since World War II, when the president's party has controlled the White House for two or more terms, the incumbent party has won just one-third of the ensuing elections.

Why will such small margins be so consequential for Republicans? Call it the curse of overreaching: today's mostly moderate public is unlikely to reward a majority party that pursues an ideologically polarizing agenda. Large majorities can suffer the consequences of a disaffected public, but slim majorities in an era of polarized parties cannot. As I suggest below, slim congressional majorities face distinct procedural hurdles to achieving their policy goals, hurdles that will affect their party's electoral future adversely.

To detect the impact of slim majorities, consider first the electoral context in which the Republican majority must maneuver. Today's legislative parties are extremely polarized, with few moderate legislators left in the political center. Although polarization has been increasing over the past two decades, most Americans remain solidly in the ideological middle.⁶

Yet despite the Republicans' narrow majorities and Americans' centrist tendencies, Republican majorities have governed as if with a sweeping conservative mandate. Bush's policy proposals in 2001 were ambitious and, as many have noted, “off-center,” including tax cuts, education vouchers, faith-based initiatives, and privatization of social security—an agenda crafted to appeal to the Republicans' conservative base.⁷ Bush's interpretation of the 2004 election summed up his party's view best: “I earned capital in the campaign, political capital, and now I intend to spend it.”⁸ If mandate elections are marked by their sweeping scope and unexpected character, then Bush's stock of political capital is unlikely to buy him and his party much success in his second term.⁹

Could overreaching by slim majorities in today's electoral environment cost Republicans control of the House or Senate? My hunch is yes, given the policy and procedural consequences of narrow majorities. Slim majorities make majority coalitions tough to build and to sustain. A handful of defections can cost the majority its coalition.¹⁰

Moreover, we know from two centuries of House politics that small, cohesive majorities are especially prone to manipulate the rules of the game to their advantage; threatened by minority obstruction, majorities alter the rules to secure their policy goals.¹¹ Not surprisingly, given the difficulty of building winning coalitions, Republican House majorities since 2001 have relied much more heavily than did their predecessors on restrictive rules: nearly half of all special rules in the 108th Congress (2003–4) allowed the minority party to offer just one substitute amendment on the floor or allowed no amendments at all. Such limitations on the minority have been deemed necessary by Speaker Denny Hastert, given the GOP's narrow margin of control and the lack of Democratic votes for GOP initiatives.¹²

In a legislative body with so few centrist members, reliance on restrictive rules that limit votes on moderate alternatives is bound to produce more ideologically polarized outcomes—as evidenced by GOP legislative victories on economic policy (for example, enactment of tax cuts heavily skewed to upper income taxpayers) and on social policy (for example, intervention in the end-of-life decisions of Terry Schiavo). In structuring votes between an unacceptable vote for the status quo and a vote for a polarized alternative, centrist members of the majority party are often unable to vote for outcomes that best reflect their constituents' preferences. Such votes at times cost centrists their seats, as moderate Democrat Marjorie Margolies-Mezvinsky learned the hard way in 1993 after voting for President Bill Clinton's budget.

Senate Republicans have been equally aggressive—to the extent chamber rules allow—in exploiting the rules of the game to secure more polarized outcomes. The use of multiple reconciliation bills has protected Republican initiatives from both Democratic filibusters and Republican moderates who might otherwise vote against cloture.¹³

And stung by Democratic filibusters and wavering moderates, Republican leaders have sought to “go nuclear”—despite a disapproving public—to ban filibusters on judicial nominations.¹⁴ These procedural tactics are made necessary given the narrow margin held by a conservative chamber majority seeking noncentrist outcomes.

Can overreaching on policy and procedure cost Republicans control of Congress? To the extent that Republicans succeed in securing their party's policy goals, resulting legislation is more likely to be off-center, catering to the majority's base. Conversely, to the degree that Republicans falter in pursuing their agenda, they are likely to be blamed for inaction. Neither outcome is likely to be rewarded over the next decade by a persistently moderate public. In fact, public approval of both the president and Congress had slipped markedly by spring 2005. In March 2001, 55 percent of the public approved of the way Congress was doing its job; four years later, just 37 percent approved—its lowest rating in almost a decade and a far cry from the 84 percent who gave Congress high marks after the attacks of September 11.¹⁵

President Bush's approval rating at the same time—the end of the first one hundred days of his second term—was under 50 percent.¹⁶ Summary evaluations of the president have, of course, strongly predicted the vote in nearly every election in postwar America.¹⁷ Moderate publics are unlikely to sustain unified—and often overreaching—Republican rule over the decade to come.