Keating is a McCain campaign co-chair.

(CNN) - A prominent surrogate for John McCain on Thursday raised Barack Obama's admitted cocaine use as a teenager and said the Illinois senator should speak candidly about it to the American people.

Speaking to Dennis Miller, a comedian and conservative radio talk show host, former Oklahoma Gov. Frank Keating said Obama should be more forthright about his background and what he called his "very extreme" record.

"He ought to admit, ‘You know, I've got to be honest with you. I was a guy of the street. I was way to the left. I used cocaine. I voted liberally, but I'm back at the center,'" Keating, a co-chair of McCain’s campaign, said Obama should tell voters. "I mean, I understand the big picture of America. But he hasn't done that."

An aide to John McCain said Keating was not directed by the campaign to make the comments.

"We didn’t ask him to do it,” the aide said. “He didn’t clear it with us, but obviously he’s read Senator Obama’s books.”

The Obama campaign has not responded to the comments.

The remarks ring similar to comments made by prominent New Hampshire Democrat Bill Shaheen, a Hillary Clinton supporter, during the primary. Shaheen predicted in December that Obama’s drug past would be a major Republican talking point if her were the Democratic nominee. He later apologized for the comments, but stepped down from his role in the Clinton campaign. Black Entertainment Television founder Bob Johnson, another Hillary Clinton backer, also had to apologize after making overt references to Obama's drug use at campaign rally in South Carolina.

In Obama's 1995 book Dreams of My Father, he writes that he was once headed in the direction of a "junkie" and a "pothead. Referring to his emotional struggles as a young man, Obama writes, "Pot had helped, and booze; maybe a little blow when you could afford it. Not smack, though."

Obama did speak during his primary campaign about his past experimentation with drugs and alcohol in high school.

"I made some bad decisions that I've actually written about," he told New Hampshire high school students last November. "There were times when I, you know, got into drinking, experimented with drugs. There was a whole stretch of time where I didn't really apply myself a lot."

The RNC will begin airing a new ad Friday that mentions William Ayers.

(CNN) – Republican efforts to link Sen. Barack Obama to William Ayers, a member of a 1970’s anti-war terrorist group, will increase Friday when a new ad from the Republican National Committee hits the airwaves.

Related: Ayers, Obama crossed paths on boards, records show

“Chicago Way,” attempts to cast Obama as a stereotypical “shady” Chicago politician. Shot in black-and-white, the ad asserts “Obama’s first campaign was launched at a gathering at Mr. Ayers's home.”

The ad also mentions convicted Chicago businessman Tony Rezko, a onetime prominent supporter of Obama’s, and William Daley, a national co-chair of Obama's presidential campaign who is also the brother of Chicago Mayor Richard M. Daley and the son of legendary Chicago political boss Richard J. Daley.

Related: Daley slams new McCain ad

“There’s more you need to know,” an announcer says as the ad ends.

The ad comes as the McCain campaign continues to carry out a more aggressive strategy of raising questions about Obama’s judgment and personal associations in the last month of the general election campaign. Alaska Gov. Sarah Palin recently said that Obama sees America as “so imperfect that he's palling around with terrorists who would target their own country,” in an apparent reference to Ayers.

Related: Get the facts about Palin's charge

The Obama campaign has hit back hard accusing the McCain of trying to distract voters’ attention away from the many challenges the country is facing.

The RNC says "Chicago Way" will air in major media markets in Indiana and Wisconsin.

(CNN) - Democratic vice presidential nominee Sen. Joe Biden is set to join Jay Leno on "The Tonight Show," Obama-Biden spokesman David Wade tells CNN.

This will be Biden's first late-night talk show appearance since being named to the number two spot on the Democratic ticket. Beau Biden, Biden's son, appeared on the late-night mainstay on September 16.

Sen. Biden, who was recently parodied on "Saturday Night Live" after his debate against Gov. Sarah Palin, will appear on the talk show on October 16.

The Obama campaign has previously run a two-minute commercial; today it announced has purchased 30-minute blocks of time on the broadcast networks.

(CNN) – Barack Obama is buying 30 minutes of airtime on the major television networks just days before the presidential election, the Obama campaign confirms.

Sources with the Obama campaign say half hour blocks have been purchased on Wednesday, October 29 on CBS and NBC.  The campaign is also in negotiations with Fox, though that day will conflict with the World Series if there is a game 6.

The buy was first reported by the Hollywood reporter earlier Thursday.

Evan Tracey of Campaign Media Analysis Group, CNN's consultant on ad spending, said it was unclear how much the blocs of air would cost, but noted 30 seconds alone in primetime usually runs between $80,000 and $125,000.

"This is a big platform, this is a big megaphone, the interest level is clearly there and people will watch," Tracey said.

An ethics watchdog group has asked the Senate to investigate whether Sen. McCain failed to disclose gambling winnings.

(CNN) – Ethics watchdog group Citizens for Responsibility and Ethics in Washington, commonly referred to as “CREW,” has requested that the Senate Ethics Committee investigate whether Sen. John McCain failed to disclose gambling earnings as required by federal law and the Senate’s own rules.

Click here to read CREW's request

Citing recent press reports, CREW alleges that McCain failed to disclose income earned from gambling on the personal financial disclosure forms he’s required to file as a senator. “Given Sen. McCain’s history of gambling on a regular basis over the years, it is nearly impossible to imagine that he never won over $200, the amount that triggers the reporting requirement,” CREW’s request says.

In the event the Senate Ethics Committee finds that McCain failed to disclose any gambling earnings, the watchdog group asks that the matter be turned over to the Department of Justice for a criminal investigation into whether McCain knowingly and willfully failed to disclose any winnings.

The McCain campaign has not responded yet to CNN’s request for comment about CREW’s request for an investigation.

The Alaska Supreme Court has refused to put a stop to an investigation into Gov. Palin's firing of the state's public safety commissioner.

ANCHORAGE, Alaska (CNN) - An investigation into Alaska Gov. Sarah Palin's firing of her public safety commissioner can proceed, Alaska's Supreme Court ruled Thursday, clearing the way for a Friday report to the state Legislature on the issue.

The justices rejected an effort to halt the probe by the Republican vice presidential nominee's allies in the Legislature, who called the investigation an attempt by partisan Democrats to sabotage the GOP ticket.

The justices unanimously upheld an Anchorage judge's ruling last week that dismissed theRepublican lawsuit and upheld subpoenas for top Palin allies.

The former commissioner, Walt Monegan, has said he was fired in July after refusing pressure to sack Palin's ex-brother-in-law, State Trooper Mike Wooten. Palin denies any wrongdoing, saying Monegan was dismissed after clashing repeatedly with her over budget issues.

She originally agreed to cooperate with the probe, which was launched by a bipartisan commission of the state Legislature in July. But after Sen. John McCain tapped her as his running mate in August, her advisers dismissed the investigation as "tainted" by partisan politics and began to straight-arm the inquiry.

The governor's husband Todd and several top aides spent three weeks resisting subpoenas issued by the state Senate in September. But after last week's decision by Anchorage Superior Court Judge Peter Michalski, and with Friday's deadline for the investigation's final report approaching, they agreed to give statements to a special counsel this week.

Full story

– CNN's Tracy Sabo contributed to this report.

New polls show Obama with leads nationally and in several key battleground states. (AP Photo)

(CNN) - Barack Obama continues to hold significant leads over John McCain, a fresh round of state and national polls out Thursday suggest, in what is unwelcome news for the Republican presidential nominee as Election Day inches closer and closer.

The Illinois senator now holds a 6 point lead over McCain nationwide, a new CNN poll of polls consisting of five recently released surveys show, while 8 percent remain undecided.

A string of new state polls also show Obama holding significant leads in several key battleground states, including Minnesota, New Hampshire, Ohio, West Virginia, and Wisconsin. McCain is holding onto leads in Montana and Missouri.

In Minnesota, CNN's latest poll of polls shows Obama up 11 points, 52-41 percent, while he holds a 9 point lead in CNN's latest New Hampshire poll of polls, 51-42 percent. Obama is also holding onto a 4 point lead in Ohio, 50-46 percent in CNN's latest poll of polls there.

In West Virginia, Obama holds an 8 point lead in a new American Research Group poll, though CNN's Sept. 21-23 poll of West Virginia showed McCain leading there by 4 points. In Wisconsin, a new Research 2000 poll shows Obama with a 10 point lead, 51-41 percent. CNN's Wisconsin poll earlier this month showed Obama with a 5 point lead.

In Missouri, a new CNN poll of polls shows McCain hanging onto a 1 point lead, while the Arizona senator has a 5 point lead in Montana according to a new American Research Group poll.

Obama got tough on McCain's mortgage plan Thursday.

DAYTON, Ohio (CNN) – Barack Obama called John McCain’s plan for the government to buy back bad mortgages “risky” because it leaves already burdened taxpayers with the bill.

“We have to act to fix our broken economy and restore the credit markets. But taxpayers shouldn’t be asked to pick up the tab for the very folks who helped to create this crisis,” he told an 8,000 plus crowd in a Dayton minor league baseball stadium. “It’s a plan that would guarantee that American taxpayers lose by handing over $300 billion to underwrite the kind of greed and irresponsibility on Wall Street that got us into this mess.”

Obama also got a little personal; seizing on the fact that the McCain campaign originally indicated Tuesday he supported purchasing mortgages of strapped homeowners at a discount. But by Wednesday his proposal had changed and instead called for the government to buy the mortgages at face value even if they were worth more than the home itself.

Related: Obama: McCain's mortgage plan shows 'erratic' leadership

“This is the kind of erratic behavior we’ve been seeing out of Senator McCain, you remember the first day of this crisis he came out and said the economy was fundamentally sound, then two hours later he said we were in a crisis,” Obama said. “I don’t think we can afford that kind of erratic and uncertain leadership in these uncertain times. We need steady leadership in the White House. We need a President we can trust in times of crisis.”

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Watch the event on CNN.com/live.

(CNN) - Barack Obama is holding an event in Cincinnati, Ohio this hour.

Watch the event on CNN.com/live