Barack Obama isn't exactly a household name, but the Illinois state lawmaker seems en route to stardom in the Democratic Party, which has chosen him to deliver the convention keynote address.

Obama's rise to the top has been rapid. First was the unexpected triumph in the Illinois Democratic Senate primary in March.

Then came the summertime sex-club furor that drove his Republican rival from the race. And the failure thus far of the GOP to field a replacement.

Now, the 42-year-old state senator and Harvard-educated law professor, heavily favored in his bid to become the fifth black senator in history, is taking his first steps onto the national stage as keynote speaker.

"There's no doubt about it. There has been a weird convergence of events that even six months ago I would never have anticipated," Obama said.

His voice raspy from rehearsal, Obama said he'll use his 20 minutes on the convention podium to counter Republican accusations that the Democratic Party stands for big government and big spending. Instead, he will argue that the party stands for helping people and using government to do it.

"We're interested in making sure everybody has an opportunity and kids have a shot at life," he said. "To do that, there are going to be times when it's necessary for government to step in."

An early opponent of invading Iraq, Obama said the speech will not dwell on President Bush's handling of the war or on specific policy differences with the GOP administration.

"I don't spend a lot of time focusing on Bush. I spend a lot of time focusing on where we fall short of our ideals."

The Harvard Law School graduate said he wrote a speech that is closer to Mario Cuomo's 1984 address urging Democrats to return to their roots than to Ann Richards' blistering 1988 attack on the first President Bush.

The opportunity of delivering a convention keynote address can be a frustrating one. "Whatever John Kerry wants, John Kerry gets," said Rep. Harold Ford of Tennessee, whose speech was heavily vetted by Al Gore's team at the 2000 convention.

"I've been very happy with the amount of latitude they've given me," Obama said of the Kerry campaign.

He wrote the speech himself over the course of two or three days, he said, then showed it to aides. After incorporating some of their suggestions, he shared the text with Kerry's advisers, whom he said wants revisions.

As a speaker, Obama can sound at turns like a college professor, a union activist or a down-home preacher. He said he prefers to speak off the cuff instead of working from a written text. Tuesday night will be his first experience with a TelePrompter.

In the interview, though, he said he was less concerned about the speech than other duties that befall a politician on the rise.

"My schedule is a nightmare," he said. "My concern has less to do with the speech and more to do with the need to fill in for Kerry or Edwards at the thousands of receptions and events that are taking place."

Five months ago, Obama had more elementary political concerns, those of a state senator struggling in a multi-candidate senatorial primary. Obama had a compelling story: His father was a member of Kenya's Luo tribe, born on the shores of Lake Victoria. He met Obama's mother, who was white, when both were students at the University of Hawaii.

When Obama was 2, his father left the family, returning to Kenya, where he eventually became a senior economist in the Ministry of Finance. Obama grew up to receive degrees from Columbia and Harvard universities, and now is an instructor at the University of Chicago Law School.

But one rival's campaign unraveled when unsealed divorce records showed he struck an ex-wife on the leg and allegedly threatened her.

And Obama gained momentum when he began airing commercials that portrayed him as the successor to the late Sen. Paul Simon, a hugely popular former senator from downstate Illinois. The spot featured Sheila Simon talking about how her father and Obama had worked together.

The nomination in hand, Obama became the instant favorite to defeat Republican Jack Ryan in his Democratic-leaning state. But that campaign had scarcely begun when unsealed divorce records showed Ryan's ex-wife had accused him of taking her to sex clubs and asking her to engage in public sex.

Ryan denied the charge, but Illinois Republicans deserted him and he quit the campaign.

That was nearly a month ago, and so far, Republicans have no replacement.

Sen. Hillary Clinton finally ended all the speculation about her presidential ambitions over the weekend, declaring her candidacy on her Web site. In doing so, she instantly became the one to beat in a crowded field of wannabes.

In fact, a new CBS News poll shows Clinton holding a 17-point edge over Sen. Barack Obama among Democratic voters.

"It will be a great contest with a lot of talented people," Clinton said Sunday – "a lot" being the operative word.

Clinton told CBS Evening News anchor Katie Couric on Monday that she is proud of her husband's White House record and wants to build on it.

"I could go on for a long time about all the good things that were done for the country and America's position in the world during the eight years of my husband's administration," Clinton said. "And I would like to get back to building on what works … recommending the kind of bold, but practical changes – like universal health care, like energy independence – that were not possible in the first Clinton administration."

Iraq may be one of the biggest issues on the campaign trail, and Clinton reiterated to Couric that she opposes the "escalation the president has proposed."

"Unfortunately, the fact is he is carrying out the policy. He already had in motion the movement of troops into Iraq," Clinton said. "What we're trying to do is send a bipartisan message, if possible, that we disapprove of this escalation, that we want to begin a phased redeployment that I have called for more than a year and a half – that we want to get our troops home as soon as possible."

In her first appearance after Saturday's announcement, New York's junior senator upstaged two other contenders who announced their entry into the race: New Mexico Gov. Bill Richardson, a fellow Democrat, and Sen. Sam Brownback, who admitted his quest for the Republican nomination is something of a fantasy.

"My family and I are taking the first steps on the yellow brick road to the White House," Brownback, R-Kan., said at a rally in Topeka.

It might be easier to get an audience with the Wizard of Oz than steal Clinton's thunder right now. Whether Democrat or Republican, others seeking the job found themselves scrambling to acknowledge her dominance without coming across as irrelevant.

"I think she's incredibly formidable and has got to be the front-runner and the odds-on pick right now," Sen. Joe Biden, D-Del., said Sunday.

"I think she'd be a very formidable candidate," Sen. John McCain, R-Ariz., said.

At this point, only McCain polls in the high 40s with Clinton. That's with 22 months to go before the election and a lot of unknowns ahead, including the staying power of Barack Obama, the young Illinois senator, who's currently Clinton's closest Democratic rival.

But as the presumed front-runner with more than $13 million in her war chest, unprecedented name recognition and a full Senate term under her belt,
Clinton cuts a unique figure, one she says will enable her to win.

"I'm in, in to win and that's what I intend to do," she said.

Of course, Clinton steps into the fray with plenty of negatives. She's regularly called one of the most divisive people in politics, but her team says they heard all of this before.

Clinton told Couric that regarding those who question her delectability, "I would say, give me a chance.

"As a friend of mine said the other day, I am the most famous woman that nobody really knows. Because I've been caricaturized to some extent, and I want to let people make their own decisions," Clinton added. "And I think that I can do that as I have in here in our state."

Howard Wolfson, a senior adviser to Clinton, conceded that there were those who did not like her.

"There are Republicans that don't like her. At the end of the day there are a set of Republicans who won't vote for any Democrats," he told CBS News' The Early Show on Monday.

Wolfson pointed to a new Washington Post-ABC News poll showing Clinton is the favorite of 41 percent of Democrats, more than double the support of any of her rivals, to refute claims that she can't win.

"For people who wonder whether Senator Clinton can win, we say Senator Clinton is already winning in the polls," he said.

Asked how the Clinton campaign will deal with some of the scandals of her husband's presidency, Wolfson said, "I don't think voters care about those."

He said former President Bill Clinton "is her biggest supporter and always gives her advice. He campaigned for her in 2000, in 2006; everywhere he went he was a big success. We are looking forward to him on the campaign trail."

Sen. Clinton was scheduled to start a three-day series of Web chats with supporters Monday evening. She travels to Iowa, site of the first nominating caucuses to select delegates to the party's national convention, next weekend.

"As I said when I launched on Saturday, 'let the conversation begin' because I think through that conversation we'll be able to chart the best course for our country," Clinton told Couric.

Clinton and Obama are the most visible candidates in a Democratic field that includes the 2004 vice presidential nominee, John Edwards. Other candidates include Connecticut Sen. Chris Dodd, former Iowa Gov. Tom Vilsack and Ohio Rep. Dennis Kucinich.

Clinton told Couric she has "no doubt" Obama is "an extraordinarily talented person, and I am pleased we have such a talented field. I think we're going to have a great debate."