In 166 days, Americans will go to the polls to elect the next Congress. It will be one of the most consequential votes in modern history. If Republicans retain control of the House and Senate, President Trump will feel vindicated and emboldened, while reluctant “Never Trump” Republicans will be tempted to hold their noses and embrace a winner. But if Democrats take back at least one congressional chamber, Republicans may begin to stand up to a president who promised endless “winning” — but lost instead. Regardless of which party you’re rooting for, all Americans should be able to agree on one thing: The vote must be clean and free of manipulation. In a democracy, citizens must never accept rigged elections. In our new book, “How to Rig an Election,” we showcase striking findings from our research: A large number of elections across the globe are heavily manipulated. Increasingly, elections are becoming contests that are designed so that only the incumbent can win. Across the world, the opposition wins elections only about 30 percent of the time – and the figures are much, much lower in Africa, Southeast Asia, the Middle East and post-Soviet Eastern Europe. Elections without democracy has become the new normal. Nonetheless, don’t make the mistake of thinking that American elections, or those in Britain, are perfect. They aren’t.