The first night of genuine action at the Republican National Convention inverted the usual order of speakers' importance.
New Jersey Gov. Chris Christie, the keynoter, spoke last. But the message of Ann Romney, who spoke before him, carried more significance for the prospects of her husband, Republican candidate Mitt Romney.
Christie, a rising Republican star, delivered a message more consistent with his own political persona than Romney's. Delivered forcefully, it linked his autobiography with his characteristically blunt, pugnacious style. (Read More: Republican Convention Is in Full Throated Roar.)
But Christie's speech spent relatively little time praising Romney. And its dominant theme — that America needs politicians with the guts to tell difficult truths — ill-suits a Romney campaign agenda that at once promises tax cuts, higher defense spending, protected Medicare benefits and lower deficits. (Read More: GOP Platform May Dilute Romney's Focus on Economy.)
Ann Romney's speech, however, aimed directly at the Romney campaign's top-priority target: forging a more personal connection between her husband and swing voters, especially women.
Romney did that by telling voters she was speaking "from my heart about our hearts," by describing their courtship, and saying they have "a real marriage" rather than the storybook variety.
Republican and Democratic political strategists alike said she was effective in a testimonial whose summation was "you can trust" him. (Read More: Kudlow: The Star of Tuesday Night Was Ann Romney!)
Neither speech, or the ones on Wednesday night by former Secretary of State Condoleezza Rice and vice presidential candidate Paul Ryan, will prove as significant as Romney's on Thursday night. But in a close election — and surveys currently show President Obama with only a razor-thin lead — even small boosts can make a big difference.
—By CNBC's John Harwood