Does Deflecting Swat redirect a spell targeting your commander to another target?

Deflecting Swat says: 'If you control a commander, you may cast this spell without paying its mana cost. Change the target of target spell or ability with a single target.' This is a straightforward target-changing effect governed by CR 114.7 and the rules for spells that change targets (see CR 116.3 and the card's own oracle text).

When an opponent casts a spell or activates an ability with a single target aimed at your commander, you may cast Deflecting Swat in response (CR 116.2b — instants can be cast any time you have priority). It changes that spell or ability's target to any other legal target of your choice, redirecting the threat away from your commander.

The key restriction is that the spell or ability must have exactly one target (CR 114.7 specifies you must choose a new legal target for it). If the spell targets multiple objects, Deflecting Swat cannot redirect it. Also, the new target must be a legal target for that spell or ability at the time of resolution (CR 114.7).

Concrete example: Your opponent casts Doom Blade targeting your Atraxa, Praetors' Voice. You cast Deflecting Swat for free (since you control Atraxa, your commander). You change Doom Blade's single target from Atraxa to your opponent's own Vampire Nighthawk. Doom Blade now destroys Nighthawk instead.

Note that Deflecting Swat does not counter the spell — the spell still resolves, just against the new target. This is different from counterspells (CR 701.5).