Republican presidential candidate Chris Christie opened the second GOP primary debate by taking shots at former President Donald Trump. Minutes after the debate began on Wednesday, Christie was asked if Trump's populism was to blame for a possible government shutdown.

The Trump campaign called on the Republican National Committee to cancel the “boring and inconsequential" debates.

Former New Jersey Gov. Chris Christie accused former President Trump of being afraid to defend his record against fellow Republican opponents and “ducking” them.

Seven Republicans battled it out in California, while Donald Trump - who is leading in the polls - visited Michigan.

The Trump campaign called on the Republican National Committee to cancel the “boring and inconsequential" debates.

From criticism of unruly behavior to the viral "Donald Duck" comment, users flocked to social media to talk about moments from Wednesday's debate.

Chris Christie took aim Wednesday at former President Trump for missing the second GOP primary debate. Driving the news: Christie accused Trump of being "afraid of being on stage and defending your record.