NEW BRUNSWICK, N.J. — Four years of increasing activism and growing political awareness recently brought Lacey Rzeszowski to Rutgers University here, to a packed room of nearly 280 women, each on the cusp of launching a bid for public office for the first time.

Spurred by the 2012 shooting rampage in Newtown, Conn., she had pressured local and federal lawmakers on gun control legislation, first on the backs of postcards and then in live confrontations in town halls and congressional offices. Her advocacy led to calls for her to run for office, but Ms. Rzeszowsk had repeatedly declined.

Now, seeking solace and inspiration following the 2016 presidential election and the Women’s March on Washington, Ms. Rzeszowski, 42, is squaring off in a tough race against a local Republican for a seat in the New Jersey Assembly.

Political activism of all persuasions, ignited largely in response to President Trump, has swelled in the wake of the 2016 election. A monsoon of marchers swept through Washington following the inauguration, letters and phone calls flooded the White House and Congress, and protests erupted at congressional town hall meetings across the nation. But in the social media age, where protest movements often remain relegated to cable news screens and hashtags, some have wondered whether the fervor and energy would be reflected in local, state and federal ballots.