(Adds suspect's mental health history)
By Scott Malone
Aug 27 (Reuters) - The slaying of two competitors at a Jacksonville video game tournament on Sunday has stirred the long-simmering gun rights debate in Florida on the eve of its hotly contested state and federal primary elections.
With Florida voters scheduled to pick candidates for governor and Congress on Tuesday, some Democratic contenders said the shooting was further evidence of the need for stricter gun legislation while other hopefuls canceled campaign appearances.
"We as society have to come together and say enough of this," Democratic U.S. Senator Bill Nelson told reporters in Jacksonville, near the site of the shooting at a Madden 19 online football game tournament.
The violence, which also injured 11 people, was the latest in a series of high-profile shootings in the state, following the killing of 17 students and educators at a high school in February and the massacre of 49 people at an Orlando nightclub in 2016.
The Jacksonville Sheriff's Office identified the shooter, who took his own life, as David Katz, 24, of Baltimore. Witnesses told local media Katz was angry because he lost the tournament.
Katz was hospitalized twice as a teenager for mental illness and prescribed anti-psychotic and anti-depressant medications, the Baltimore Sun reported, citing his parents' divorce filings.
Reuters could not independently confirm the report.
Nelson's re-election campaign is facing a November challenge by the state's Republican governor, Rick Scott, in one of the key races that will determine the balance of power in the Senate.
Gun rights, which are covered by the Second Amendment of the U.S. Constitution, are one of the most contentious themes of American politics. The debate breaks along party lines, with Republicans typically arguing that better enforcement of existing gun laws is the best way to deter shootings, while Democrats call for more restrictions on weapons ownership.
Given the partisan breakdown, the shooting may not change outcomes in Tuesday's primaries where people will pick candidates from within their own parties.
State Agriculture Commissioner Adam Putnam, one of the Republicans seeking to succeed Scott as governor, canceled a campaign event in Jacksonville and on Twitter said his "prayers continue to be with the victims and their families."
Democratic front-runner Gwen Graham called on Putnam and his leading Republican rival, U.S. Representative Ron DeSantis, to offer a stronger policy response.
"@AdamPutnam and @RonDeSantisFL are avoiding Jacksonville because they are scared to answer questions on gun violence," Graham said in a Monday Twitter post.
DeSantis spokesman Stephen Lawson said it was not the time to talk policy.
"We chose not to politicize a tragedy," Lawson said. "This is a sad attempt to score a quick political point while families are still grieving. Shame on you."
One of the people slain was Elijah Clayton, 22, of Woodland Hills, California, a representative of his family told reporters on Monday. The other was Taylor Robertson, 27, of Ballard, West Virginia, local media reported, citing family members.
Robertson, a husband and father, won the tournament last year and Katz won it the year before, according to Madden publisher EA Sports, the unit of Electronic Arts Inc, which sponsored Sunday's tournament.
Katz had two handguns and extra ammunition but appeared to have fired only one gun, Jacksonville Sheriff Mike Williams said at a news conference. Katz bought the guns, at least one of which was equipped with a laser sight, legally in Maryland, Williams said.
Williams said the shooter targeted other gamers.
"The suspect walked past patrons who were in other parts of the business and focused his attention on the gamers," he said. (Reporting by Scott Malone in Boston; additional reporting by Colleen Jenkins in Winston-Salem, North Carolina; Letitia Stein in Tampa, Florida; Bernie Woodall in Fort Lauderdale, Florida; Joey Roulette in Jacksonville, Florida; Rich McKay in Atlanta and Gina Cherelus in New York Editing by Alison Williams, Bill Trott and Lisa Shumaker)