Democrat Debbie Mucarsel-Powell will challenge Republican Carlos Curbelo to represent voters living in a sprawling Miami-to-Key West district. She doesn't live in the district now, but history shows she has a handy fallback in the Florida Keys.

When Mucarsel-Powell ran for office in 2016 — an ultimately unsuccessful bid for a state Senate seat — she changed her voter registration two months before Election Day from an out-of-district Pinecrest home she has owned since 2009 to an in-district rental property 60 miles away in the Keys. It was a gambit that allowed her to criticize her competitor for living outside of the district.

"My opponent can't vote for herself," Mucarsel-Powell tweeted a few weeks before Election Day. "Why should the voters of SD 39?"

After the vote, she switched her registration back to Pinecrest — raising the question of whether she ever really lived in the Keys, or simply rented an apartment there because it was good politics. A questionable residency could be fodder for Curbelo and Republicans looking to keep his swing seat.

Mucarsel-Powell declined to comment Tuesday. When asked by The Miami Herald, her campaign produced a lease for a rental property in Islamorada signed on Oct. 9, 2016. The $3,000-a-month lease was set to end in January 2017, but Mucarsel-Powell switched her voter registration to Pinecrest in December. Mucarsel-Powell and her husband have three school-age children.

In an interview Monday announcing her candidacy, Mucarsel-Powell acknowledged currently living outside the 26th congressional district and made no claim that she'd plan to move there — though she said she rents property in the Keys and would love to live there.

"That's where my heart is," she said.

Members of Congress aren't required to live in the districts they represent.

In 2016, Mucarsel-Powell was in the midst of an expensive state Senate campaign against Anitere Flores, a Republican with a massive campaign warchest.

But Flores and Mucarsel-Powell shared the same political disadvantage: Neither candidate lived in the sprawling Senate District 39, which closely mirrors Curbelo's congressional district, at the start of the campaign.

In October, Mucarsel-Powell changed her voter registration from her Pinecrest home to Islamorada, according to voting records in Miami-Dade and Monroe counties.

Four weeks later, on Nov. 5, she touted her vote on Twitter.

"Debbie Mucarsel-Powell and her husband Robert cast their ballots today in Islamorada!"

A November 2016 Herald story highlighting candidates who didn't live in their districts identified Mucarsel-Powell as "Democrat Debbie Mucarsel-Powell of Islamorada." But in December 2016, after losing to Flores by about 8 percentage points, Mucarsel-Powell changed her voter registration back to her Pinecrest home, about 5 miles outside the congressional district.

"She basically just moved there so she could vote for herself and use it to hit her opponent," said Steven Ferreiro, Flores' campaign consultant. "When she was running against Sen. Flores, she made a big deal about how Flores doesn't live in the district."

Flores has since moved into the district, Ferreiro said.

Curbelo lives about a mile outside the district, in West Kendall. He lived inside the district before the Florida Supreme Court ordered its boundaries redrawn in 2015.