As mass shootings continued to rock the nation, gun control groups and leading Democrats stepped up their push for stricter gun control laws. A national poll in May found that more than 60 percent of registered voters supported stiffer measures, including more-extensive background checks and a ban on the sale of assault weapons. The 2018 midterm elections marked the first national election in which gun control groups outspent the National Rifle Association (NRA), which has been beset by internal feuds. But gun-rights groups remain formidable, and most congressional Republicans oppose tougher gun laws, saying background checks and other measures are ineffective. Amid the debate, the federal government released figures showing that firearms were involved in nearly 40,000 deaths — nearly two-thirds of them suicides — in 2017, the most in decades.