Rep. Debbie Wasserman Schultz, ousted last month from her perch atop the Democratic Party, is fighting to hold onto her House seat and now is facing criticism for scheduling a weekend debate with a surging challenger that few voters may have actually seen -- while indicating she won't face him again before their Aug. 30 primary. 

In the South Florida race, even the local Fort Lauderdale, Fla., Sun-Sentinel took a shot at Wasserman Schultz for setting debate “terms” that resulted in the incumbent facing off against primary challenger Tim Canova early Sunday morning.

“The 8 a.m. start time fuels the argument that Wasserman Schultz only wants to hold debates at inconvenient hours with limited viewership,” the opinion piece said, noting she also helped arrange Saturday-night debates during the presidential primaries that were seen as aiding Hillary Clinton.

If the congresswoman has her way, Sunday's congressional debate will be the last opportunity for voters to see the candidates square off. Canova proposed a second and third debate, but Wasserman Schultz seemed to decline, citing their primary being just two weeks away, on August 30.

Canova, though, has enjoyed a surge of support thanks in part to the endorsement of ex-presidential candidate Bernie Sanders. He’s hauled in nearly $3 million so far – most of it from out of state -- and has been the only one of the two candidates running polished political ads on Miami-Fort Lauderdale TV, hammering the incumbent for allegedly being tied to corporate donors and interests.

Time will tell whether his message resonates: Early voting begins Monday in Miami-Dade County, ahead of the Aug. 30 primary for the 23rd Congressional District seat.

The two candidates traded charges at their debate Sunday morning, with Wasserman Schultz accusing Canova, a law professor, of being inconsistent in his position on Israel.

"My opponent has been mealy-mouthed and waffling in his position on Israel from Day One," she said in the roughly 60-minute debate on CBS’s WFOR-TV in Miami. “He's taken three different positions in the last eight months."

Wasserman Schultz -- backed by President Obama and Democratic presidential nominee Hillary Clinton -- also disagreed with Canova’s suggestion that she did not have the support of black voters in the district.

Wasserman cited in part the backing of the Congressional Black Caucus. 

The candidates also battled Sunday over the Obama administration’s Iran nuclear deal, which lifts economic sanctions in exchange for Tehran curtailing efforts to make a nuclear weapon -- a deal critics call a threat to Israel.

Canova had said he supports the 2015 deal, but now says he doesn’t know how he would have voted had he been in Congress.

“I went over that deal backwards and forwards,” said Wasserman Schultz, who voted for the multi-nation agreement amid criticism about Israel’s future safety and guidelines for inspecting nuclear sites.

Canova also tried to suggest that Wasserman Schultz did not support increasing Social Security benefits, in a district with a large retiree population. Wasserman said she repeatedly has used “my vote and my voice” to increase benefits.

It’s unclear whether the debate, or the Sanders-fueled donations, will make the difference for Canova. The Canova campaign touted polling released at the end of the Democratic National Convention showed him trailing by 8 points, 46-38 percent.

This was after she stepped down at the DNC amid a scandal over leaked emails. 

But Wasserman Schultz is not taking any chances, bringing in heavyweights like House Minority Leader Nancy Pelosi. In some ways, the race is reminiscent of the Sanders-Clinton race.

"This race has a lot of parallels with the national Democratic primary in that you have a moderate candidate competing against a more progressive candidate,” said Brian Fonseca, director of the Florida International University Institute for Public Policy. “Just look at the endorsements of Wasserman Schultz and Tim Canova. Backing Wasserman Schultz is Clinton, Obama and Biden. And backing Tim Canova is Bernie Sanders." 

Fox News’ Phil Keating contributed to this report.