WASHINGTON • The latest object of US President-elect Donald Trump's ire, African-American civil rights leader John Lewis, suffered a cracked skull while fighting for voting rights 50 years ago.
Mr Lewis, a long-time Georgia congressman, said he will be boycotting Mr Trump's inauguration ceremony on Friday because he sees Mr Trump's election as illegitimate.
"Russians participated in helping this man get elected. And they helped destroy the candidacy" of his Democratic opponent Hillary Clinton, the 76-year-old Democrat told NBC's Meet The Press talk show last Friday.
An angry Mr Trump, who has repeatedly rejected suggestions that alleged cyber attacks by Russia helped him win the election, fired back early on Saturday.
In a pair of Twitter posts, he said Mr Lewis "should spend more time on fixing and helping his district, which is in horrible shape and falling apart (not to mention crime infested) rather than falsely complaining about the election results.
"All talk, talk, talk - no action or results. Sad!"
Mr Trump's Twitter tirade came two days before today's Martin Luther King holiday in the US, honouring the slain civil rights leader with whom Mr Lewis, 76, worked closely in the 1960s.
Many expressed indignation at the outburst, pointing out the unseemliness of attacking a civil rights leader just before Martin Luther King Day.
Mr Lewis was one of the original Freedom Riders, beaten by police officers during a march in Alabama.
"Ahead of #MLKday 2017, let us remember that many have tried to silence @repjohnlewis over the years. All have failed," House Democratic Leader Nancy Pelosi said in a tweet.
Others ridiculed Mr Trump's characterisation of Mr Lewis' district, which is majority African-American and encompasses three-quarters of Atlanta, as "horrible," "falling apart" and "crime infested".
Georgia's Fifth Congressional District, in fact, includes parts of rich areas like Buckhead; the world's busiest airport, Hartsfield-Jackson; the Centres for Disease Control and Prevention; and the Georgia Institute of Technology.
Some pointed out that fighting with Mr Lewis diverted attention from a Senate probe, announced on Friday, that will look at possible contacts between Mr Trump's campaign team and Russia.
Mr Trump returned on Saturday evening with a more conciliatory message: "Congressman John Lewis should finally focus on the burning and crime-infested inner- cities of the US. I can use all the help I can get!"
The feud carried echoes of Mr Trump's attacks on Mr Khizr Khan and his wife Ghazala, the Pakistani- American parents of a US soldier killed in Iraq, after Mr Khan spoke out against Mr Trump at the Democratic National Convention. Those attacks were widely viewed to have backfired. Mr Trump himself has experience questioning a president's legitimacy. He was instrumental in sowing doubts about President Barack Obama's birthplace.