SNEAK PEEK: McKinnon Lays Down His Sword

A top adviser to John McCain said Wednesday that he will not work for McCain in the general election if Barack Obama is the Democratic nominee.

"I would simply be uncomfortable being in a campaign that would be inevitably attacking Barack Obama," said McCain adviser Mark McKinnon in an interview with NPR's "All Things Considered." "I think it would be uncomfortable for me, and I think it would be bad for the McCain campaign."

McKinnon, who was a Democrat before serving as President Bush's ad maker in 2000 and 2004, said that he plans to be behind McCain "100 percent" no matter who the Democratic nominee is.

He explained, however, that if the Democrats nominate Obama, his support for McCain will have to come "from the sidelines."

While saying that he does not agree with Obama on every issue, McKinnon gushed about the Democratic frontrunner.

"I met Barack Obama, I read his book, I like him a great deal," said McKinnon. "I disagree with him on very fundamental issues. But I think, as I said, I think it would a great race for the country."

Audio of McKinnon's interview with NPR's Michele Norris is available here.

Will McKinnon's comments make it harder for McCain to tout Obama's National Journal rating as "the most liberal senator" of 2007?

Can McCain bring up Obama's support for raising Social Security taxes?

How about Obama's one-time pledge not to play "chicken with the troops"?

What about his support for driver's licenses for illegal immigrants?

Is any of this fair game?

Or would it only be "bad for the McCain campaign"?

As they say in television, only time will tell.

On the campaign trail. . .

JOHN MCCAIN

-- 11:00 am ET: Attends rally with voters, South Burlington, VT

-- 11:45 am ET: Holds media availability, South Burlington, VT

-- 1:30 pm ET: Attends rally with voters, Warwick, RI

-- 2:15 pm ET: Holds media availability, Warwick, RI

MIKE HUCKABEE

-- 12:00 pm ET: Attends rally with voters, Madison, WI

-- 1:00 pm ET: Holds media availability, Madison, WI

-- 3:00 pm ET: Attends rally with voters, La Crosse, WI

-- 4:00 pm ET: Holds media availability, La Crosse, WI

-- 6:00 pm ET: Attends rally with voters, Rothschild, WI

-- 7:00 pm ET: Holds media availability, Rothschild, WI

-- 9:00 pm ET: Attends rally with voters, Green Bay, WI

-- 10:00 pm ET: Holds media availability, Green Bay, WI

As for the Democrats. . .

HILLARY CLINTON

-- Attends event in Youngstown, OH

-- 6:00 pm ET: Attends rally with John Glenn and Governor Ted Strickland, Columbus, OH

At the White House. . .

PRESIDENT BUSH

-- 10:10 am ET: Delivers remarks on Africa policy, Washington, DC

-- 7:35 pm ET: Attends Valentine's Day social dinner with the First Lady, Washington, DC

-- 9:00 pm ET: Attends Valentine's Day entertainment with the First Lady, Washington, DC

Also. . . -- 10:00 am ET: U.S. Capitol Memorial Service to Honor Chairman Tom Lantos, Washington, DC

POLITICAL NEWS STORIES AT ABCNEWS.COM

ABC News' David Wright Reports: Obamamentum: Can Sen. Clinton Stop the Train? LINK

ABC News' Jennifer Parker Reports: Clinton's Delegate Math Challenge LINK

ABC News' Rick Klein and Raelyn Johnson Reports: Edwards Weighs Clinton Endorsement LINK

ABC News' Gary Langer Reports: White Men Boost Obama; McCain Wins Amid Doubts Over Conservative Cred LINK

ABC News' Jake Tapper Reports: What McCain's Campaign Means by "Mathematically Impossible" LINK

ABC News' Jennifer Parker Reports: Obama, McCain Sweep Potomac Primaries LINK

ABC News' Teddy Davis Reports: McCain Adviser Won't Fight Obama LINK

ABC News' Jake Tapper Reports: Dem Delegate Fight Pits Sharpton Vs. NAACP LINK

ABC News' Jake Tapper Reports: Hillary Goes Negative on TV LINK

ABC News' Sunlen Miller Reports: Obama: McCain 'Traded Principles for His Party's Nomination' LINK

ABC News' David Wright, Andy Fies and Sunlen Miller Report: Is the Democratic Nomination Locked Up? LINK

ABC News' Jake Tapper Reports: Gary Hart: How Super Delegates Did Me In in '84 LINK

ABC News' Eloise Harper and Kate Snow Report: Clinton Hears Voice from Beyond: 'Keep Going' LINK

ABC News' Jake Tapper Reports: Should Political Journalists Vote? LINK

ABC News' Bret Hovell and Seiko Hayashi Report: McCain: Obama's Positions 'Singularly Lacking in Specifics' LINK

ABC News' Kate Snow and Eloise Harper Report: Clinton: 'This Is the Exciting Part' LINK

ABC News' Bret Hovell and Seiko Hayashi Report: McCain: It Would Be Easier if Huckabee Was Out LINK

ABC News' Jake Tapper Reports: I Just Called to Say I Love You LINK

ABC News' Luis Martinez Reports: Defense Sec. Gates Breaks Shoulder from Slipping on Ice LINK

ABC News' Jake Tapper Reports: Puerto Rico Gov. to Back Obama LINK

ABC News' Teddy Davis Reports: Incumbents Go Down in Maryland LINK

ABC News' Z. Byron Wolf Reports: Playing D for McCain on Torture LINK

ABC News' Sunlen Miller Reports: Obama 'Takes It Down a Notch' LINK

ABC News' Luis Martinez Reports: Sec. Gates Back to Work with Arm in a Sling LINK

POLITICAL VIDEO AT ABCNEWS.COM

Obama, McCain On Top
ABC's Rick Klein on what's next in the presidential race. LINK

Potomac Primary Aftermath
A week after Super Tuesday, front-runner advantage emerges. LINK

Clemens Stumbles on Capitol Hill
During congressional hearing, baseball player struggled to find the right words. LINK

McCain: Would Be Easier if Huckabee Dropped Out
McCain: "Of course I'd like for him to withdraw today. It would be much easier." LINK

On The Trail: Edwards Campaign Wrap After six months on the campaign trail, reporters became like family. LINK

McCain: Obama Message 'Lacking in Specifics'
Sen. McCain accuses Sen. Obama of offering broad generalities in his '08 run. LINK

Clinton Ad Goes Negative on Obama
Clinton releases ad asking Obama why he hasn't agreed to debate in Wisconsin. LINK

Clemens Takes the Stand
The baseball player is set to testify on steroid use in Major League Baseball. LINK

The Bottom Line on the Potomac Primaries
George Stephanopoulos takes a look at what's ahead for the candidates in '08. LINK

Obama Sweeps Again
The Illinois senator wins in Maryland, Virginia and Washington, D.C. LINK

Dems Have a New Frontrunner
Winning 175 delegates in the Potomac primaries, Obama gets an edge on Clinton. LINK

Huckabee Hangs in the Race
Former Arkansas governor's campaign is "disappointed but not knocked out." LINK

'Clean Sweep of the Chesapeake!'
GOP front-runner John McCain enjoys victorious night of three primary wins. LINK

Obama Dominates Potomac Primary
Illinois senator says "change" swept across the Chesapeake and over the Potomac. LINK

Clinton Moves Campaign to Lone Star State
On the eve of the Potomac primary, Sen. Clinton hosts rally in El Paso, Tex. LINK