Former President Donald Trump is stepping up his election-year effort to dominate the Republican Party with a Saturday rally in Arizona in which he plans to castigate anyone who dares to question his lie that the 2020 presidential election was stolen, likely including the state’s GOP governor, Doug Ducey. But 2,000 miles to the east in Washington, there are small signs that some Republicans are tiring of the charade. Mike Rounds, the generally unassuming senator from South Dakota, was perhaps the boldest in acknowledging the reality that the election was in fact fair. Instead of being shunned, he was supported...