Republicans can only win by cheating. Because they can't win based on ideas & ability to govern.
That's how Democrats can only win. For decades, they stacked California and a few other states with illegal aliens, to stuff the ballot boxes with their (illegal) votes. The do all they can to bring the illegals in, and then protect them in sanctuary cities (ex. redent congressional vote to cut off funds to sanctuary cities)
They also ran TV ads with rampant lies (ex. the disabled reporter, McCain, Khizir Khan, outsourcing, the laughable-phony 13 alleged women victims of Trump misbehavior, etc)