Presidential historian Douglas Brinkley responds to President Donald Trump's tweet that appeared to be mocking a reference to the Trail of Tears, the forced relocation of thousands of Native Americans which led to thousands of deaths, and a subsequent post by Donald Trump Jr. online.

CNN contributor Douglas Brinkley says Jared Kushner, senior adviser to President Trump, should be concerned about special counsel Robert Mueller's court filing that stated former Trump national security adviser Michael Flynn gave "substantial evidence" to the Russia investigation.

CNN presidential historian Douglas Brinkley compares the firing of former FBI Deputy Director Andrew McCabe to former President Richard Nixon's "Saturday Night Massacre."

Two presidential experts weigh in on whether or how the tax bill will help the president.

Presidential scholar Douglas Brinkley on unusual criticism of President Trump by his predecessors.

CNN's presidential historian Douglas Brinkley discusses the similarities and differences between Reagan and Trump.

The Washington Post is reporting that Gov. Chris Christie and Newt Gingrich are leading the list for Donald Trump's potential running mate. CNN's Carl Bernstein and Douglas Brinkley weigh in on if the choices will help Trump.

The Obama administration will unveil a major climate change plan Monday aimed at a large reduction in greenhouse gas emissions from the nation's coal-burning power plants, a senior administration official told CNN. CNN's Fredricka Whitfield reports.