WASHINGTON — On the chilly grounds of the National Mall, within sight of the gleaming white Capitol where he is on trial for high crimes and misdemeanors, President Trump on Friday rallied abortion opponents gathered for their annual march and equated their battle with his own.

“They are coming after me,” Mr. Trump declared about a half-hour before the day’s trial session opened, with two of the juror-senators joining him onstage, “because I am fighting for you and we are fighting for those who have no voice. And we will win because we know how to win. We all know how to win. We all know how to win.”

For Mr. Trump, the strategy to win these days is counterprogramming. While Democrats and Republicans debate whether he should be convicted and removed from office, the president has offered up an alternative menu of events intended to focus attention on his economic record, present himself as a peacemaker and cater to his conservative base.

As the trial opened in earnest this week, he was hobnobbing with global corporate titans in Davos, Switzerland, trumpeting the growth of jobs and markets back home. As the House managers prosecuting him wrapped up their case on Friday, he became the first sitting president to attend the March for Life, bolstering his ties to the anti-abortion movement. And as senators begin posing their own questions next week, he plans to host Israeli leaders and release his long-awaited Middle East peace plan.