The discovery of pipe bombs targeting prominent Democratic politicians and CNN is raising the threat of election-season violence largely unknown in the U.S. — and prompting uncomfortable questions about the consequences of leaders’ increasingly vitriolic rhetoric.

A sprawling investigation unfolded Wednesday as authorities scrambled to respond to a series of suspicious packages addressed to the homes of two former presidents, the offices of CNN and a former chair of the Democratic National Committee.

A bomb has been found at the home of Hillary and Bill Clinton in a New York City suburb, according to the Associated Press.

An object that appeared to be an explosive device was found in a mailbox at the home of George Soros, the billionaire liberal philanthropist who is a frequent target of right-wing conspiracy theories. 

Protesters ambushed Senator Ted Cruz and his wife at an upscale Italian restaurant last week. 

Stellar ratings and an apology weren't enough to mitigate Roseanne Barr's racist comments, and now ABC is pulling the plug on "Roseanne."

U.S. stocks were smacked again Thursday, with the Dow industrials falling as much as 400 points as Wall Street joined a global rout that came as investors worried about the global economy and Chinese moves to weaken its currency.