The Republican Party, as many observers have noted, is facing the prospect of a long-term decline as a national political party. Since 1992, they have lost four out of the last six presidential elections. And of the other two, in 2000 they lost the popular vote (and quite possibly the electoral vote too if Florida had been accurately tallied); in 2004 they won with just 50.7 percent of the vote.

My own view is that Trump will very likely continue this losing streak. But leaving that aside for now, there is no doubt that the Republicans face serious structural problems at the national level. These include changing demographics (their base is overwhelmingly white); the increasing unpopularity of their core ideas; the long-term failure of their economic policies (including some that continued to be advanced and implemented during the Bill Clinton era); the extremism of their electoral base, which makes it more difficult for the party to choose a presidential candidate that can possibly win the general election; and increasing divisions, including along class lines, within the party (which we can see in the Trump insurgency).

What, then, appears to be the strategy for a declining political party in the Republicans’ situation? It is clear that there are two major elements that have come to the fore in recent years. One is voter suppression, i.e., to reduce the number of voters with a bias toward keeping likely Democratic voters away from the polls. The array of “voter identification” laws passed in recent years is an attempt to reduce turnout: for example, the 2011 law in Wisconsin that requires voters to present government-issued identification in order to vote. It is pretty well established that these laws have nothing to do with preventing fraud. Indeed, the Wisconsin law was originally thrown out by the courts for this reason, only to be reinstated on appeal. (Friday’s decision by the US Court of Appeals for the Fourth Circuit, invalidating a voter identification requirement in North Carolina, could be a significant blow to the national voter suppression effort.)

The second element is gerrymandering of districts for the House of Representatives. The Republicans have been able to do this by winning control of many state legislatures, which redraw the congressional district boundaries every 10 years, in accordance with the census (most recently in 2010). Since Obama took office in 2009, Republicans won 30 state legislative chambers (913 legislators), 11 governors, and 69 members of the House of Representatives. Although the party opposing the president typically makes some gains in these arenas, these are very large by historical comparisons.

The Republicans have had some advantages at the state and local level: local media tends to be more conservative than the national media, and some big Republican donors (e.g., the billionaire Koch brothers) have funded this strategy, since Obama became president, of using state governments to hang onto power by shifting the rules for national elections in their favor.

The two strategies are related, since they are both implemented at the state and local level. But I would like to focus on voter suppression, because it raises serious questions about the legitimacy of the Republican Party. If a political party can only be competitive under a system in which a large majority of the adult population (e.g., in US congressional elections) does not vote, how legitimate is that party? Prior to the Voting Rights Act and the Civil Rights struggle of the 1960s, millions of African-Americans in the South were excluded from voting. It was this system of disenfranchisement that allowed racist, segregationist politicians to be elected and re-elected, to have powerful positions as committee chairs in Congress, and to block voting and civil rights reforms for many years.

We do not have the same impediments to voting today that Black people faced in the South in the pre-Civil Rights era. Nonetheless, they are sufficient to make the United States an exceptional country in terms of low voter turnout. Most democracies hold their elections on a non-workday, e.g., a Sunday. They also do not have so many laws and restrictions that keep people from voting, such as requirements for advance registration, and for reregistration after moving. As a result of this “American exceptionalism,” the US recently ranked 31 out of 34 countries in the OECD (a group of mostly high-income countries), in voter turnout. And that was based on the 2012 presidential elections in the US, with a 58.3 percent turnout. Non-presidential election years are vastly worse; in 2014 only 35.9 percent of eligible voters participated.

That leads to the question of how different our government would be if we had normal levels of voter participation. It seems very likely that it would be quite different, and that Republican chances of winning a majority in Congress would fall drastically, and their already low chances of winning the presidency would also plummet.

A study by the Pew Research Center in November 2012 found that nonvoters favored Barack Obama over Mitt Romney by a margin of 59 to 24 percent, while likely voters were evenly divided. Only 27 percent of nonvoters identified as “Republican or lean Republican,” as compared to 52 percent “Democrat or lean Democrat,” whereas likely voters were again evenly split.

These differences between nonvoters and votes are enormous, and they help explain why voter suppression has become so important to Republicans in recent years. More survey data is needed, especially for non-presidential election years, where the Republican strategy has given them a grip on the House that is tough to break. But it is pretty clear that voter disenfranchisement is the bedrock of Republican power. As such, the legitimacy of the Republican Party is questionable.

More broadly, this country needs voting reform that can put an end to this form of “American exceptionalism,” just as the civil rights legislation of the 1960s put an end to the disgraceful era of African-American disenfranchisement.

Mark Weisbrot is Co-Director of the Center for Economic and Policy Research in Washington, D.C., and the president of Just Foreign Policy. He is also the author of the new book “Failed: What the ‘Experts’ Got Wrong About the Global Economy“ (2015, Oxford University Press). You can subscribe to his columns here.