Obama-Romney: Whom do you trust?

President Obama is playing the trust card against Mitt Romney -- the Romney forces call it a desperation deal.

In blasting what he calls "Romnesia" -- his opponent's habit of changing positions -- Obama told backers Tuesday in Ohio, "Now, we joke about Governor Romney being all over the map, but it speaks to something important -- it speaks of trust.

"There's no more serious issue in a presidential campaign than trust," Obama said during a rally in Dayton. "Trust matters. You want to know that the person who's applying to be your president and commander in chief is trustworthy, that he means what he says, that he's not just making stuff up depending on whether it's convenient or not."

Obama said Romney has changed or is hiding details on such issues as tax cuts that would benefit the wealthy, education assistance and his opposition to the auto bailout.

Romney aides said voters trusted Obama four years ago, and he let them down.

"President Obama broke virtually every promise that candidate Obama made in 2008, including his pledges to turn around our economy, cut the deficit and change politics as usual in Washington," said Romney spokesman Ryan Williams.

He said, "The president's tired and dishonest political attacks will do nothing to distract voters from his abysmal record of broken promises and lack of any new ideas for the future."

The Obama-Romney race looks very close, especially in the Electoral College, and any issue could tip it one way or another.

Whom do the voters trust? The answer could determine the presidency.