In what may be the sleeper legislative campaign of the season, Sen. Gwen Margolis, the veteran Democrat from Miami, is getting a run for her money — literally — from Miami Beach lawyer John Couriel in the newly drawn coastal district.

Margolis has loaned herself $160,000 to win reelection to Senate District 35, which stretches from Golden Beach to Homestead. But she is being outraised and, so far, outspent by Republican newcomer John Couriel, a Miami Beach lawyer.

Couriel, 34, has collected $213,830 in campaign contributions to Margolis’ $174,093 and has won the endorsements of former Gov. Jeb Bush and U.S. Sen. Marco Rubio. A Harvard-educated lawyer, Couriel quit his job as an assistant U.S. attorney in Miami to run for the seat and vows to out-campaign Margolis, 78, a former state Senate president who was first elected to the state House in 1974.

“I’m hustling. I’ve never done this before but I’m not going to be outworked,’’ Couriel said Monday during a break from walking door-to-door in Pinecrest.

Couriel has the trappings of broad Republican support, from the endorsements of party icons Rubio and Bush to a political committee running attack ads against his opponent. But there is one notable absence: his race is not among the must-watch contests receiving cash infusions from the Senate Majority, the political committees controlled by incoming Senate leader Don Gaetz, R-Niceville.

At a meeting with reporters last week, Gaetz singled out the races that could produce upsets and Couriel v. Margolis wasn’t among them.

“Sen. Gaetz and I are friends,’’ Margolis said Monday, noting that the Niceville Republican lived for years in her Miami Shores district and supported her.

Couriel says he is undaunted that he’s not getting more attention from Senate leadership. “I am assuming I need to do this on my own,’’ he said.

He said he’s running because he believes voters want a change. “The purpose of public office is not to honor someone by electing them to office. We elect someone to work for us and I’m running because I think I could do a better job.”

The district trends Democratic, with nearly 60 percent voting for Obama in 2008 and Alex Sink in 2010. But Democrats do not make up a majority of the district — 45 percent are registered Democrat, compared to 28 percent registered as no party affiliated and 27 percent registered Republican.

Couriel believes he can reach independents and crossover voters with his moderate Republican message. He ticks off the statistics in previous races to make his case.

“Rick Scott doesn’t do well here,’’ Couriel said, but Republican Chief Financial Officer Jeff Atwater barely lost the district in 2010 and Rubio beat Democrat Kendrick Meek in the U.S. Senate race. “That tells me that many Democrats are soft.’’

Margolis has been a fixture in Miami-Dade politics for decades, and Couriel must not only introduce himself to voters but bring down Margolis’ image in the process, an expensive task in the long coastal district.

“To effectively run an aggressive campaign against Sen. Margolis is going to take a lot of money,’’ said Christian Ulvert, a Margolis advisor and Democratic consultant.