DENVER – Mitt Romney is set to kick off the most important stretch of his presidential campaign, a time when he said he will use his three debates with President Barack Obama to set the record straight on his vision for the country and to stump more vigorously in swing states.

The Republican nominee spent the weekend huddled with advisers and with Sen. Rob Portman, R-Ohio, who has been playing Obama in mock debate sessions.

Romney said the debates, the first of which is Oct. 3, will give him a chance to push back against what he said were distortions by the Obama campaign on the auto bailout, his record on abortion and tax rates for the middle class.