A similar situation exists for the District of Columbia and other territories such as Guam and the United States Virgin Islands. Those in the territories also do not have the ability to vote in presidential elections.

Still, Mr. Rosselló’s departure and the resignation this week of his acting representative in Washington leaves Ms. González-Colón as the only link between its residents and the Capitol. It also opens an opportunity to replace him as governor, an ambition she is widely believed to harbor.

[Read about how the governor of Puerto Rico misread the anger brewing against him.]

Ms. González-Colón and Mr. Rosselló are members of the same Puerto Rican political party and even ran on the same 2016 ticket, but the relationship has not always been amicable. Her ties to the governor’s Washington representatives were strained, and when Mr. Rosselló tumbled into scandal this month with the publication of vulgar messages between him and his staff, she called the messages shameful and urged him to drop any plans for re-election.

She said this week that no one had consulted her about her replacing Mr. Rosselló, a possibility should she be appointed to the now-vacant post of secretary of state, first in the line of succession. (Wanda Vázquez, the secretary of justice, is now first in line to replace Mr. Rosselló, but faces opposition.) And Ms. González-Colón refused to talk about running for the office in 2020, saying, “I don’t think public officials should be wondering or speculating about what can happen, or about their political ambitions” during the crisis.

But in the same breath, she noted that her campaign to become resident commissioner garnered more votes in 2016 than any other candidate for office in the territory.