'The parasite is slowly taking over the host': Some Republicans flee Trump, back Clinton

Inside one of the big white media tents that dot the landscape around the site of the Democratic National Convention, Ricardo Reyes is making a pitch for Hillary Clinton. 

He chimes in on party politics, as a guest on a low-budget YouTube talk show.

With Philadelphia swarming with Democrats this week, it's not unusual to hear yet another plea for Clinton votes.

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But Reyes is not a Democrat. He is a life-long Republican from California, and his goal is to stop Donald Trump, the Republican presidential nominee, from winning the November election. 

"Some of the things he espouses are very, very dangerous," he  tells a YouTube talk show. 

Reyes calls Trump a xenophobic isolationist who is "completely irresponsible on national security issues."

So Reyes and fellow Republican John Stubbs, who both worked in the White House under George W. Bush, started an election campaign of their own. They founded a grassroots group, Republicans for Clinton 2016.

"I have voted for Republicans, I have worked for Republicans, I have given money to Republicans. So this is a new space for me", says Stubbs.

Watching in horror

Reyes says he chuckled when Trump joined the race to become the Republican nominee. He did not take Trump seriously, and he says he watched in horror when Trump won. 

"He is not a real Republican, " says Reyes, who calls himself an old-school Republican with a "deep-seated belief in the open market."

Reyes says the GOP let extreme, racist elements change it and slowly take it over. He compared them to parasites.

Trump is 'the head of the parasite'

"The parasite is slowly taking over the host and now with Trump, he's the head of the parasite taking over the Republican Party."

Reyes says he has lost track of how many media interviews he has done since coming to the DNC.  

During a break in his schedule, he dips a piece of pita in a container of peanut butter, and nibbles on a grape and a slice of apple. 

"It's breakfast," he laughs at 3 p.m.

"We have a meeting with some Facebook folks," says Reyes. 

"And interviews with Associated Press and USA Today," says Stubbs , barely looking up from his cellphone. 

They are trying to get the word out to fellow Republicans who dislike Trump that not voting isn't an option.  

They maintain the only way to defeat Trump is to elect Clinton.

"Republicans have been trained a long time to believe that Hillary is the enemy, so getting to a place where they could see pressing a button or pulling a lever for her is a challenge."

That might be an understatement, considering Republicans chanted "Lock her up, lock her up" repeatedly at their convention in Cleveland last week. 

Reyes says he came around to believing he could vote for Clinton by looking at her record as a senator. He maintains she worked closely with Republicans.

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Hank Paulson, former U.S Treasury secretary and a prominent Republican, is also voting for Clinton. 

"A Trump presidency is unthinkable," he wrote in a letter in the Washington Post recently. 

Michael Bloomberg, the former mayor of New York who has been a Democrat and a Republican and now is an independent, made a passionate appeal for Clinton in front of a large convention crowd Wednesday night.

"There are times I disagree with Hillary," he said.

"But whatever our disagreements might be, I have come here to say we must put them aside for the good of the country. We must unite around the candidate who can defeat a dangerous demagogue."