Mr. Trump, and other Republican officials, can help by setting aside plans to interfere. One attempt at sabotage suffered a setback on Monday when a federal judge rejected an effort by Texas Republicans to toss more than 127,000 ballots from drive-through polling stations in Harris County, which includes Houston. Ben Ginsberg, a longtime lawyer for the Republican Party in voting cases, including in Florida in 2000, broke ranks in that case. “Not so long ago, it was a core tenet of the Republican Party that the vote of every qualified voter should be counted, even if, at times, it did not work in the party’s favor,” Mr. Ginsberg wrote. That should be a core tenet for both parties in the coming days.