AT FIRST glance, there wasn’t much to the way Sens. Barack Obama and John McCain dressed for the debate Tuesday in Nashville, other than their partisan choices in necktie color -- a pale shade of blue for Obama and red stripes for McCain. Both wore two-button, notch-lapel jackets with a single vent in the back (Obama’s was black, McCain’s was dark charcoal). Both wore white dress shirts with a spread collar.

But like a “magic eye” painting, the longer you looked, the clearer the picture became, and as the candidates paced the red-carpet ring, their divergent styles popped into view.

What emerged? Obama wore his suit, and McCain’s suit wore him. Tall and lanky, the Democratic nominee came off as confident and at ease in his custom-tailored ensemble, which showed just the right amount of shirt cuff, the dimple in his necktie just off center. His Republican counterpart looked uncomfortable -- every inch a career military man for whom the dress uniform seemed a necessary evil, but combat fatigues are an easy fit.

When the situation is less formal, McCain carries the day. His April stroll through a Baghdad market in a blue shirt and bullet-proof vest had near John Wayne swagger, while Obama on a bike ride in a polo shirt and a pair of high-waisted dad jeans came off like Urkel from “Family Matters.” That’s no small matter when so much political perception centers on how “approachable” and “real” a candidate seems.

But projecting authority is still the No. 1 task, and that means tailoring matters -- putting McCain at a disadvantage. Although the McCain camp did not respond to confirm the fact, the senator’s suits look off the rack. Style-wise, they’re totally off the mark; the jackets hang too low for his height (he’s 5 feet, 7 inches), they’re too wide in the shoulders and the arms are too long.

The armholes are either too big or sit too low, which causes the sides of his jacket to “bat-wing” a bit. And the torture he endured as a prisoner of war left him with a stiffness of carriage that further emphasizes the outsized look. In sum, the impression is more David Byrne in the Talking Heads’ movie “Stop Making Sense” circa 1984 than White House contender circa 2008.

It’s unfathomable to think that the 25-year veteran of Washington arrives at debates unaware of his appearance -- especially in light of a recent report that he shelled out more than $5,000 to a makeup artist to prep him for a TV appearance. The more likely scenario is that it’s part of his straight-talking modus operandi to reject any wardrobe wisdom as pure gimcrackery.

Still, he’s made some small adjustments along the way. On Tuesday night, he chose a darker suit and swapped out the bold red-and-white tie from the previous debate that conjured images of candy stripers and barber poles. And that scored points with style experts.

“It was about the best dressed I’ve seen [McCain] in the debates,” said Alan Au, vice president of Beverly Hills’ Jimmy Au’s, a store that specializes in dressing men 5 feet 8 and under. “The tie was very sharp and presidential and didn’t steal focus. The darker suit made it a little harder to see the problem with the armholes.”

In the details

Obama, a twice-crowned cover god of Men’s Vogue, has a different style approach. He’s clearly aware of the effect of every last detail. (It wasn’t always this way; early in his campaign, Obama occasionally appeared with shirt collars far too big for his neck -- which emphasized his comparative youth).

The junior senator from Illinois (who stands 6 feet, 1 1/2 inches) favors custom-tailored suits from 121-year-old Chicago clothier Hart Schaffner Marx (we’ll spare you his jacket size and inseam). Perhaps that’s because there’s political capital in sporting a suit made by union labor in Des Plaines, Ill., a fact company representative Lisa Wells helpfully noted. Wells was unsure whether the black suit Obama wore during Tuesday’s debate was one of theirs, but it’s a pretty safe bet. Obama wore one of the label’s made-to-measure suits (two-button, navy blue, 100% worsted wool, with pleated and cuffed trousers) when he accepted the Democratic nomination, donned another style for the first presidential debate Sept. 26, and, Wells says, has five more on order.

He favors an updated take on the traditional suit -- it hangs shorter and has narrower lapels, and it works. The slim-fitting suits drape effortlessly over his frame.

At times, however, being so well put together works against Obama. At rallies, where the candidates have been known to shuck their jackets and roll up their sleeves, McCain looks as if he’s ready to frame a house, while Obama looks like an accountant baffled by casual Friday.

“It’s kind of a cliché look,” said Details magazine’s fashion director, Michael Macko. “You take off the coat and roll up the sleeves -- ‘Look, I’m a real guy.’ He might do better to wear a pair of gray pants and a navy blazer in a more casual setting. Or, he’s been known to wear a tan suit, which is a big fashion step for a politician. If he did that and then took his jacket off, he’d look like he was wearing khakis, which would seem more casual without looking forced.”

The verdict: Obama seems to have gotten better marks from the fashion press overall, but both candidates would be wise in the final days of the campaign to remember they aren’t just playing to the base.

adam.tschorn@latimes.com