By By Yukio Strachan Jul 18, 2012 in Politics "Tricky Mitt" is his name and not releasing tax returns is his game, suggests a new TV ad launched Wednesday showing Mitt Romney morphing into Richard Nixon posing the question: "He's not a crook... right?" The liberal group may be taking its cue from Obama's re-election campaign, which has run its own ads asking what Romney could be hiding. Both seem to be seeking to leverage the ever-louder drumbeat from the president’s camp – and some Republicans – for Romney to disclose more of his tax returns, the Conservatives fretting about Romney's response to the barrage of attacks from Obama are focused mostly on the Republican's reluctance to shed more light on his personal fortune, estimated to be up to $250 million, Unlike most politicians seeking national office, Romney initially declined to release any of his tax returns. In January, under pressure from his opponents in the Republican primaries, he released his 2010 return and an estimate for 2011. (footage below) The ad isn't the first time the Republican presidential candidate has been compared to President Nixon over transparency issues. In an interview with CBS Radio News earlier this month, senior campaign adviser David Axelrod called Romney, "the most secretive candidate we've seen probably since Richard Nixon." The comparison plays into the Democrats' larger narrative that Romney is a dishonest politician who may be lying about his business record or hiding information about his taxes. In response to Axelrod's comments, the Romney campaign charged that the Obama campaign was trying to distract voters from the president's record on the economy. "With millions of Americans suffering in the Obama economy, it's no surprise that President Obama and his allies would resort to false, negative attacks in an attempt to distract Americans from the President's abysmal record," campaign spokeswoman Amanda Henneberg told CBS Radio News. In what CBS news says may be one of the harshest ads of the 2012 campaign season yet, the liberal grassroots group MoveOn compares Romney with former Republican President Richard Nixon, whose devotion to secrecy contributed to his impeachment and resignation in 1974.The liberal group may be taking its cue from Obama's re-election campaign, which has run its own ads asking what Romney could be hiding.Both seem to be seeking to leverage the ever-louder drumbeat from the president’s camp – and some Republicans – for Romney to disclose more of his tax returns, the Miami Herald says.Conservatives fretting about Romney's response to the barrage of attacks from Obama are focused mostly on the Republican's reluctance to shed more light on his personal fortune, estimated to be up to $250 million, Reuters reported.Unlike most politicians seeking national office, Romney initially declined to release any of his tax returns. In January, under pressure from his opponents in the Republican primaries, he released his 2010 return and an estimate for 2011. (footage below)The ad isn't the first time the Republican presidential candidate has been compared to President Nixon over transparency issues.In an interview with CBS Radio News earlier this month, senior campaign adviser David Axelrod called Romney, "the most secretive candidate we've seen probably since Richard Nixon."The comparison plays into the Democrats' larger narrative that Romney is a dishonest politician who may be lying about his business record or hiding information about his taxes.In response to Axelrod's comments, the Romney campaign charged that the Obama campaign was trying to distract voters from the president's record on the economy."With millions of Americans suffering in the Obama economy, it's no surprise that President Obama and his allies would resort to false, negative attacks in an attempt to distract Americans from the President's abysmal record," campaign spokeswoman Amanda Henneberg told CBS Radio News. More about Mitt Romney, Richard nixon, Moveon, Romney tax return More news from Mitt Romney Richard nixon Moveon Romney tax return