In response to the terror attacks in Brussels, US presidential candidates have ramped up their rhetoric. Two candidates competing for the Republican nomination said they would approve the use of torture and special police patrols for Muslim neighbourhoods.

It didn't take long for presidential hopefuls in the United States to cite the Brussels terror attacks as grounds for security measures that many consider barbaric.

Like water boarding - a form of torture that feels like drowning. Republican front runner Donald Trump said as president he would authorize water boarding and he wouldn't stop there.

"We are allowing thousands of people to come in here, nobody knows where they are from, nobody knows who they are, and they are coming in here by the thousands and let me tell you something, we are going to have problems, just as big or bigger than they got," Trump said.

Another Republican candidate, Ted Cruz, called for U.S. police departments to "patrol" to "secure" Muslim neighbourhoods to preempt terrorism.

"We need to be directing our efforts at stopping that from happening... stopping isolated communities from festering Jihadism," Republican presidential candidate Ted Cruz said.

Democratic front-runner, Hillary Clinton criticized her Republican opponents-saying their words could damage America.

"We can't throw out everything we know about what works and what doesn't and start torturing people. What Donald Trump, Ted Cruz and others are suggesting is not only wrong...it's dangerous," Hillary said.

Such criticism hasn't hurt either candidate.

"These are 'red meat' appeals to many Republican voters. Trump has done very well. Cruz has done very well. So two of the toughest Republicans are left standing," said Darrell West, vice president of Governance Studies, Brookings.

"The more moderate voices within the Republican Party have been forced to drop out, because they were not getting the votes."

In the nation's capital, skepticism over the comments.

"I think that there should be some sort of interrogation. I don't believe that torture is necessary."

"It's a cause and effect to everything. So if we react then they react and more people get hurt."

Despite widespread criticism that the 'tough guy' talk on terrorism crossed a line, recent polls show it's done nothing to dent the popularity of Trump and Cruz among this country's conservative voters.