Romney: Trump's KKK response 'disgusting'

Mitt Romney on Monday assailed Donald TrumpDonald John TrumpKoch-backed group launches six-figure ad buy against Heitkamp Anti-abortion Dem wins primary fight Lipinski holds slim lead in tough Illinois primary fight MORE’s response to support from former Ku Klux Klansman David Duke as rendering him unfit for the White House.

“A disqualifying and disgusting response by @realDonaldTrump to the KKK,” tweeted Romney, the GOP’s 2012 presidential nominee.

“[Trump’s] coddling of repugnant bigotry is not in the character of America,” Romney added.

Duke urged listeners on his radio show last week to vote for Trump, arguing that supporting Sens. Marco RubioMarco Antonio RubioRubio: McCabe 'should've been allowed to finish through the weekend' For Tillerson, bucking Trump became a job-killer At least six dead after pedestrian bridge collapses on cars in Florida MORE (R-Fla.) or Ted CruzRafael (Ted) Edward CruzCruz says Cambridge Analytica assured him its practices were legal Dem battling Cruz in Texas: ‘I can understand how people think this is crazy’ Overnight Tech: Facebook faces crisis over Cambridge Analytica data | Lawmakers demand answers | What to watch for next | Day one of AT&T's merger trial | Self-driving Uber car kills pedestrian MORE (R-Texas) instead would be “treason to your heritage.”

Trump evaded questions about Duke’s support during a Sunday interview with CNN, saying he doesn't fully understand the positions of the former KKK grand wizard.

“I don’t know anything about David Duke,” he told anchor Jake Tapper on “State of the Union.”  “I don’t know anything about what you’re talking about with white supremacy or white supremacists. I know nothing about white supremacist.”

Trump on Monday said a “lousy earpiece” caused a misunderstanding during the interview.

“You could hardly hear what [Tapper] was saying,” he said. “What I heard was ‘various groups.’  I have no problem disavowing groups, but I’d at least like to know who they are.  It’d be very unfair disavowing a group if they shouldn’t be disavowed.”

Romney’s criticism of Trump marks the latest escalation of his feud with the New York business man, who is poised for big wins this week in Super Tuesday contests that could propel him to the nomination.

Romney has repeatedly attacked Trump for not publicly releasing his tax returns, arguing there is “no legit reason” for keeping the documents private.

Trump has responded by calling Romney a “a fool” for his management of the tax issue four years ago during his own presidential run. He has said he is in “no rush” to release his tax history given the complexity of his business dealings.

Updated at 2:02 p.m.