Since Donald Trump locked up the Republican presidential nomination in May, the pundit class has had one consistent thought about what his best strategic choice would be: focusing on Hillary Clinton.

But for much of the intervening period, he has seemed unable to stay focused on his opponent. From insulting the Khan family in the wake of the Democratic National Convention to the latest controversies involving various comments about women (and his defensive reactions when past comments about former Miss Universe winner Alicia Machado emerged during the first debate, and explosive audio obtained by The Washington Post was revealed in the lead-up to the second), Trump has consistently been distracted from what most experts say should have been his main mission, hitting Clinton on her many vulnerabilities.

Trump showed signs that may have finally changed at his first rally since both the second debate and the emergence of the “Access Hollywood” tape last week. At the Monday event in Pennsylvania, he didn't follow his usual course of riffing on polls — which show him losing ground precipitously anyway — and talking in generalities about immigration, national security and the economy (though he did riff on polls).

Instead, after a painful bit of pandering to Pittsburgh sports fans and a short introduction, he launched into what appeared to be a new, reworked stump speech for the home stretch — a laundry list of complaints against Clinton, beginning with her performance in St. Louis on Sunday.

Trump focused on Clinton’s use of a personal email server while secretary of state, perhaps one of his most effective lines of attack given Clinton’s historically low polling on questions of trust. And that's when he reprised a promise he first made on Sunday.

“Special prosecutor, here we come!” he said with a smile. (His campaign manager said earlier it was just “a quip.” In Pennsylvania on Monday, it sounded more like a talking point.)

The Fix’s Aaron Blake explains in this video why that is unlikely, even if Trump wins the election:

That sort of pledge may not endear him to the independent and undecided voters he needs to win the White House. But it’s still an effective line for Republican voters who see Clinton as the corrupt representation of everything that’s wrong with Washington. Trump might be struggling mightily in the polls, as his own party splinters around him — but instead of reaching out, he seems to have decided that the best strategy is doubling down.