President Trump’s reelection campaign ramped up criticism of Rep. Karen Bass (D-Calif.) on Saturday amid speculation that she could be tapped to be former Vice President Joe Biden’s running mate.

In a call organized by the campaign and led by Sen. Marco Rubio (R-Fla.) and Florida Lt. Gov. Jeanette Nuñez (R), the two lawmakers tore into Bass’s past comments on and trips to Cuba, broadcasting possible lines of attack the campaign hopes could be effective in the nation’s largest swing state.

The call centered around Bass’s past remark describing Fidel Castro as “Comandante en Jefe” in a statement she issued after his death in 2016 and trips she took there throughout the 1970s as part of the Venceremos Brigade, a group that organized visits to Cuba for leftist Americans.

“If God forbid Joe Biden is elected president and Congresswoman Bass becomes vice president, she’ll be the highest-ranking Castro sympathizer in the history of the United States government,” declared Rubio.

“I think I speak for all freedom-loving Americans in this nation, especially Cuban Americans, when I say that a vote for Biden/Bass would be a slap in the face to all of those Cuban dissidents in exile who have arduously worked and lost their lives ensuring our civil and political rights remain untouched,” added Nuñez.

The press call, which was dedicated solely to Bass and her stance on Cuba, was a chance to preview some of the attacks that will come against the Biden ticket should the California lawmaker be chosen as his running mate.

Trump and his Republican allies are confidant the line of attack could be particularly potent in Florida, a critical swing state that the president won by just over 1 percent in 2016. The Sunshine State is home to a large Hispanic population, including many immigrants from a slate of Latin American countries who fled socialist dictatorships and tilt more Republican than the Latino community across the country.

“[C]uba today is an evil, Marxist regime and…the people of Cuba deserve freedom and democracy. You have people that disagree about the best way to bring that about, but we don’t have, especially here in South Florida, a large section of our population of voting Americans who believe that what is happening in Cuba is good and we should embrace the Castro regime. That’s what Congresswoman Bass believes,” Rubio said. 

The Trump campaign has also targeted Bass over remarks she made in 2010 at a Scientology church in California, though most of GOP’s rebukes toward Bass have focused on Cuba, particularly given how tailor-made they believe the message is to Florida and its 29 critical electoral votes.

“I don’t believe in the last six decades that there has anyone considered of the vice presidency, not to mention in that position, with this level of sympathy towards a Marxist regime,” Rubio said Saturday.

Bass this week started mounting her defense against the attacks, dismissing criticism that her 2016 remark of Castro was overly deferential while noting she believes in reopening relationships with Cuba.

“For a country that is 90 miles away, for a policy that we’ve had decades [and] hasn’t worked, I think opening up relationships is the best way to go,” Bass said this week. “But I certainly understand the sensitivity and, to me saying that, the understanding that the translation in Spanish communicated something completely different. Lesson learned.”

On Saturday, she also swatted away criticism of the remarks she made at the opening of a Scientology church in Los Angeles a decade ago, saying she was trying to speak to “what I think all of us believe in — respect for another's views, to treat all people with respect, and to fight oppression wherever we find it.”

Neither the Biden campaign nor a spokesperson for Bass immediately responded to requests for comment from The Hill.

The Republican campaign against Bass is taking place ahead of Biden’s announcement of his running mate, which is expected to take place in the first couple of weeks of August. 

Biden has already declared he would pick a woman and is under pressure to pick a woman of color amid a national reckoning over systemic racism and police brutality. Bass has seen her name raised in headlines in recent days as someone who is under serious consideration to join the Democratic ticket.

Among others being considered are Sens. Kamala Harris (D-Calif.), Tammy Duckworth (D-Ill.) and Elizabeth Warren (D-Mass.), former national security adviser Susan Rice and Rep. Val Demings (D-Fla.).

Bass has allies, both in the Congressional Black Caucus, which she chairs, and in Florida who say Republicans are overplaying their hand.

“Senator Rubio’s press call today on behalf of Donald Trump was a desperate attempt to smear a woman who has spent the past decades working to further democracy in Cuba and who believes we must continue to combat the lingering impact of the Castro regime,” Raúl Valdés-Fauli, the mayor of Coral Gables, Fla., who immigrated to the U.S. from Cuba, said.

But other Democrats say Bass must address her past remarks on Cuba and her trips there more strongly to effectively put away the GOP line of attack.

“If she has any hopes of having her past not be the source of genuine damage, it starts with a full-fledged and full throated mea culpa acknowledging that it was a mistake or naïveté to have traveled so often to Cuba and said comments that on the surface appear to be sympathetic and in solidarity with the communist and totalitarian regime that oppressed, jailed and killed the family of many people today who are voters throughout the United States,” said Fernand Amandi, a Florida-based Democratic consultant and pollster.

Still, Amandi said picking Bass could violate the maxim of picking a running mate who would do no harm and would hand the GOP a line of attack “on a silver platter.”

“I think it’s clear that they’re chomping at the bit for Congresswoman Bass to be selected so they can make the election, in Florida at least, a choice as opposed to the referendum on Trump they do not want it to be,” he said.