Nationally and across Florida, Muslim-Americans have watched with fear the slow build of hostility that seems to mount with each new terrorist attack around the world.Then last week in California, a man and his wife who had pledged allegiance to the Islamic State on Facebook opened fire on a late-morning holiday party, killing 14 people. In response, Republican presidential frontrunner Donald Trump has taken anti-Islam rhetoric to a new level, saying all Muslims should be barred from entering the United States.Almost immediately, already overwhelmed Muslim leaders in Florida and around Tampa Bay were inundated with fearful phone calls and reports of anti-Muslim threats."The community is turning to us for protection, for safety, for guidance. We haven't been sleeping. … We can't keep up," said Hassan Shibly, director of the Florida chapter of the Council on American-Islamic relations. "(Donald Trump) is taking a page out of Hitler's playbook, and I don't say this lightly." While this area hosts a large Muslim population and an accepting non-Muslim community, Shibly and other local leaders say Islamophobia is rising fast everywhere, affecting Muslims locally."The environment these days is much worse politically for Muslim-Americans than the days following 9/11," Shibly said. "It actually waits for, takes advantage of and celebrates actions taken by Muslims to galvanize fear."••• Since the Nov. 13 terrorist attacks in Paris, the Anti-Defamation League has recorded about two dozen incidents nationally aimed at Muslim-Americans, said Oren Segal, the director of the league's Center on Extremism. The list includes an Uber passenger in Charlotte, N.C., who hit his driver in the head after mistakenly thinking he was Muslim, and police reports that someone fired shots at a Muslim family's home in Orlando."Whenever there is a high-profile attack nationally or internationally," Segal said, "there does tend to be a correlation in incidents aimed at the Muslim community."In Virginia, a caller left a voicemail at a mosque on Thursday threatening to kill Muslims in retaliation for the California shooting. And in South Florida on Friday, someone smashed windows and overturned furniture at the Islamic Center of Palm Beach, although police said they are not investigating it as a hate crime.On the day of the Paris attacks, violent voicemail messages were left at two Pinellas County mosques. In one, authorities said a Seminole man threatened to firebomb the Islamic Society of St. Petersburg and shoot everyone there in the head, even children.Hatem Jaber, a volunteer at the mosque, heard the threatening voicemail first. As the story drew national attention, Jaber said the phone at the mosque would not stop ringing.At least 200 people vowed their support. One man offered to stand guard outside the mosque during Friday services. Others volunteered to sleep there overnight, just in case. A Methodist Church invited the society to pass out educational pamphlets on an upcoming Sunday."Regardless of how bad it gets, you know that there's good people out there," Jaber said. But since the incident, paranoia has crept into his daily routine. Before he leaves his home for morning prayer, Jaber surveys his surroundings, just in case. He scans the yard, the road, his car. He worries about his wife, who covers herself in public, and their two young daughters.Muslim students at the University of South Florida said they are fearful of a similar backlash.Malak Fakhoury, 21, a USF senior, said she and her friends were taught from a young age to be on guard, to keep a low profile, to not dress "too Islamic." Fakhoury, who grew up in Ocala, said she has not personally been the victim of any overt anti-Muslim act. She is familiar with dirty looks, and feels an increasing unease."Every time I open Facebook, I just see a different post about some hate crime happening, or someone feeling like they're about to be targeted," she said.The other day, Fakhoury said, a friend texted her and said someone at a gas station on Fletcher Avenue had thrown a cup of soda on her, then yelled, "You don't belong here.""It kind of paralyzes you," she said. "And the worst part is that you live with the fear even though you've done nothing wrong."Sisters United Muslim Association, a student group Fakhoury is involved in, sent out an email to members last week encouraging them to report any threats to organizations like CAIR. The Muslim Student Association at USF did the same. CAIR Florida has been pushing a similar message.As anti-Muslim rhetoric gains traction, Muslims around Tampa Bay feel compelled to denounce extremists acting violently in the name of their peaceful religion."I condemn what happens. They kill people for no reason," said Abdul Hamid Atiyeh, president of Al-Aqsa Grocery, a Middle Eastern grocery store in Temple Terrace. "Why kill people? Islam is not terrorist. We are human beings."• • •In the immediate aftermath of the Sept. 11 terrorist attacks, political leaders from both parties took a stand against knee-jerk fear mongering, but experts say the recent string of terrorist attacks happening in the midst of a heated presidential election have allowed negative opinions about Islam in the United States to boil over."It's not on the fringes any longer, it seems to be the mainstream," said Ken Gude, a senior fellow with the national security team at the Center for American Progress, a liberal think tank.In an attempt to tamp down anti-Muslim rhetoric, President Barack Obama spoke Sunday night from the Oval Office, saying, "It is the responsibility of all Americans, of every faith, to reject discrimination. It is our responsibility to reject religious tests on who we admit into this country."Within 24 hours, Trump called for "a total and complete shutdown of Muslims entering the United States."U.S. Sen. Marco Rubio, also a presidential candidate, asked in response to Obama's speech where the "widespread evidence'' is that discrimination against Muslims is a problem.Shibly said any perception that there is no real problem in the United States is skewed because less than 1 percent of Muslim-Americans who experience discrimination report it. Islamophobia is a broad umbrella, he said, and discrimination can range from overt hate crimes to name-calling.Social media, he said, has only made the spread of misinformation easier and quicker.At the same time, it has given Muslim-Americans and groups like CAIR a platform to build community and educate about Islam."They have an opportunity to respond and push back in a way that they didn't have previously," Gude said.Mahmoud Elkasaby, operations director at the Islamic Society of Tampa Bay Area, said Muslim-Americans, and especially refugees from war-torn countries, hold their breath when an act of mass violence happens."Muslims, more than anybody else, care for the safety of this country because every time something stupid happens we know fingers are going to be pointed at Muslims," he said. "We ran away from all of that to come here. So many people have given up everything to come here and have a better life. We'll never, ever, put this country in danger."Times staff writers Hanna Marcus, Kathryn Varn and Ayana Stewart and Times researcher John Martin contributed to this report, which contains information from wire services. Contact Katie Mettler at [email protected] or (813) 226-3446. Follow @kemettler.