One of the more optimistic projections of the 2018 midterms was the potential of Georgia and Florida electing progressive, African-American Governors. Alas, neither came to pass, but the outcomes may have shown two of the three tactics that the Republican Party has relied on for decades. All three are likely tactics that the party will need to rely on as they face an America becoming more diverse, tolerant and urban.
The tactic that was not in display in Florida and Georgia was gerrymandering. The idea of drawing districts that favor one party over another. Since district boundaries are drawn by the State legislatures, it's a matter of winning the State legislature and manipulating the map. I remember see an old district map of Pennsylvania where York and Dauphin counties were divided between two districts.
In Florida and Georgia, we may have seen voter suppression, especially of African-American voters. Stories of voter purges and disputed ballots in Georgia, and a refusal by Florida to allow sufficient time for the votes to be counted were all across the web and social media. There were other incidents in other states as well, and the reduction of early voting, a way that many African-Americans vote, could be evidence of this tactic.
Of course, you also have to get the right people to the polls. For the Republican Party, that means in addition to the well-to-do, you also need to bring the; low-income, less-educated, often rural voter in. This is often done through "Dog Whistling", the use of code words to incite. This is a tactic that may date back to the "Southern Strategy", if not sooner.
The question then becomes, how to fight back. This becomes a complex and interlocking process. To create fairer districts, either legal action or State legislative victories is necessary. To win State legislatures, voter suppression may need to be overcome. To counter the dog whistle, education may be necessary.
But all of these tactics are deeply embedded in the Republican Party, and one may need to remember that, much like slavery, segregation and perhaps now mass incarceration, that a long, and even bloody, struggle may be necessary.