The first United States presidential debate between President Barack Obama and Republican challenger Gov. Mitt Romney was held last Wednesday in Denver, Colorado. By all accounts, Mr. Romney prevailed, setting the tempo for the debate and making the president look listless and defensive in comparison. The GOP challenger, while dominating the debate, was also much more moderate than the candidate that had been running up to that point.

This new "Moderate Mitt" should appeal to the undecided voters who may well decide the November ballot. Two big questions remain: Will voters believe that this is the real Romney, and will a more centrist candidate alienate the Republican base?

Prior to the debate, Mr. Romney was running behind Mr. Obama. Most polls had the president ahead by as much as 5 percent (although some showed the race a dead heat).