Critics of Republican presidential front-runner Donald Trump are asking: How much lower can the incendiary, confrontational candidate go?

At this point, his sometimes insulting comments and ferocious attacks on adversaries are generating extensive blowback and may be adversely affecting his public standing. The latest Reuters/Ipsos poll finds that 31 percent of Republicans support him for their party's presidential nomination, a decline of 12 percentage points from 43 percent on Nov. 22. Retired surgeon Ben Carson is in second place with 15 percent and no one else is close, according to Reuters/Ipsos.

Trump points out that he still leads in this poll and in most other surveys at the national and state levels.

Real Clear Politics finds that, when several major polls are assessed, Trump has 27 percent support among Republicans nationally, and Carson has 19 percent.

Trump's latest dust-up, which boiled over during the past few days, stems from his mockery of a New York Times reporter while Trump was giving a speech in Myrtle Beach, South Carolina, last week. "Poor guy, you ought to see this guy," Trump told the crowd, and then he began to shake his arms erratically. The reporter, Serge Kovaleski, has a disability, arthrogryposis, that causes such mannerisms.

A spokeswoman for the Times condemned Trump for insensitivity and for trying to demean a respected journalist.

Trump, who hates to back down and loves to confront his adversaries, then demanded an apology from the Times and denied that he had done anything wrong. "I merely mimicked what I thought would be a flustered reporter trying to get out of a statement he made long ago," the real estate developer said.

He was referring to a story Kovaleski wrote for The Washington Post after the 9/11 terrorist attacks in 2001 that referred to authorities trying to determine if people in Jersey City, New Jersey, had cheered the destruction of the World Trade Center towers. Rumors about such cheering have never been substantiated, even though Trump says he witnessed these incidents. Kovaleski said he never could verify the rumors.

Trump wasn't done with Kovaleski. "He should stop using his disability to grandstand," Trump tweeted. He also said, "I have no idea who this reporter, Serge Kovalski [sic], is, what he looks like, or his level of intelligence."

But Kovaleski said he met Trump several times while covering his business activities for the New York Daily News years ago.

This tussle follows a series of other inflammatory remarks that Trump has made during his campaign, such as calling undocumented immigrants from Mexico murderers and rapists; making derogatory comments about women; mocking former Vietnam POW and current Sen. John McCain's hero status; threatening to put U.S. mosques under surveillance and possibly close some mosques if he believes they have connections to the philosophy of jihad, and dismissing his GOP rivals as losers and incompetents.

But his mockery of Kovaleski struck a nerve beyond politics. Jay Ruderman of the Ruderman Family Foundation, which promotes the advancement and rights of people with disabilities, told the Daily News, "It is unacceptable for a child to mock another child's disability on the playground, never mind a presidential candidate mocking someone's disability as part of a national political discourse." Ruderman offered Trump "a series of sensitivity training sessions."

Some establishment Republicans are fighting back, arguing that Trump is alienating so many people that he would go down to a huge defeat in the general election if he wins the GOP presidential nomination. Gov. John Kasich of Ohio is among those taking Trump on, sponsoring ads against him and calling him a bully and a divisive force. Kasich, a GOP presidential candidate, told ABC News Sunday that Trump "is not going to be the nominee. ... He may have 20 percent of the [GOP] vote, but he's got 80 percent of the Republicans who don't support him.





Former Gov. Jeb Bush of Florida, another GOP presidential candidate who has tangled with Trump in the past, told CBS Sunday, "I have grave doubts about Donald Trump's ability to be commander in chief. ... He's not a serious candidate. He doesn't talk about the issues that are of national security importance for our country."



And former business executive Carly Fiorina, also a Republican presidential candidate, told Fox News Sunday, "Apparently Donald Trump only feels big when he's trying to make everyone else look small. Of course, in the end he looks the smallest of all."