No more Mitt the nice guy.

Mitt Romney hit back this week on President Obama's aggressive attacks on his private sector record at Bain Capital, but questions remain about whether he can and should get equally tough on the campaign trail.

Romney has had arguably one of the scrappiest weeks on the presidential campaign trail, demanding an apology Thursday from the Obama team for suggesting he might he have committed a "felony" in a federal filing, then doing five TV interviews the next day in which he railed against the allegations.

Still, Obama has hammered louder and longer on the trail, which has resulted in calls for the GOP presidential candidate to roll up his sleeves and hit back on the stump.

"Romney should go on the attack if only to push back on Obama's message that 'I am not Mitt Romney,'" Tyler Harber, a GOP strategist and partner at Harcom strategies, said Friday.

Harber and others point out this presidential campaign has been exceptionally negative and at a relatively early stage.