John McCain’s campaign manager is accusing Barack Obama of unfairly using the issue of race, a significant accusation in a campaign featuring the first African-American major party nominee.

“Barack Obama has played the race card, and he played it from the bottom of the deck,” said Rick Davis, in a statement issued from the McCain campaign. “It’s divisive, negative, shameful and wrong.”

Yesterday in Missouri, Obama predicted McCain and the GOP would use racially tinged attacks against him.

“What they’re going to try to do is make you scared of me,” Obama said. “You know, he doesn’t look like all those other presidents on the dollar bills.”

An Obama spokesman denied that the line about “dollar bills” was related to the Democrat’s race.

McCain’s campaign has stepped up their attacks Obama since his overseas trip and began airing an ad yesterday comparing the Illinois senator to a vacuous pop star. But for months, both McCain and his campaign have been careful to avoid anything that approaches an assault based on race. McCain has rebuked outside parties, including the North Carolina GOP and an Ohio talk show host, whose attacks cited Obama’s controversial pastor and his middle name.

Now with the contest entering a new, more negative phase — one largely brought on by McCain — the Republican campaign is clearly seeking to preemptively rebut any attempt by Obama to attribute race to their attacks. Davis, in effect, is laying down a marker.

But by flatly accusing Obama of having “played the race card,” Davis ensures that the issue, already looming over the historic campaign, will now take a front-and-center position in a contest that is increasingly being fought more over character than issues.