Back when he first testified, Michael Cohen lied to Congress. He was accused of that, admitted it and is going to prison for it. Basically he lied about three major events.
He lied about the money paid by Trump which is a political campaign violation. He lied about not knowing about Roger Stone and Wikileaks and he lied about the date that negotiations on Trump Tower Moscow ended.
According to the original testimony he lied when he said that all talk regarding Trump Tower stopped in 2015 or early 2016 when Trump’s campaign got off the ground. It either stopped then or it stopped later. If it was a lie that it stopped in early 2016 than it obviously is true that it continued well into the campaign.
So by attacking Cohen for his lies in the original testimony the Republicans have to be conceding that the new testimony just given has to be more truthful. After all it cannot both be lies. If his original testimony was truthful and the Trump Moscow talks did end before the campaign got under way then Cohen pleaded guilty to lying when he was not in fact lying.
However if he was lying in his original testimony than the latest testimony has to be truthful. The Rethugs cannot claim that both are lies.
Besides the hypocrisy of anyone in the GOP calling anyone a liar is beyond laughable when they are supporting someone who has lied over 8000 times in the last two years.