Updated 12.28pm: Hillary Clinton is officially in the race.

The former First Lady and Secretary State wants the Democratic nomination for next year's presidential race.

Hillaryclinton.com has just gone live, and the former First Lady has posted a short video, saying she's up for the job.

"Americans have fought their way back from tough economic times. But the deck is still stacked in favour of those at the top. Everyday Americans need a champion, and I want to be that champion."

Anyone else after the Democrat nomination is expected to struggle to contend with the juggernaut that will be Hillary Clinton's campaign for US president.

US correspondent Jack Tame says the sheer infrastructure behind the Clinton campaign is astounding.

"She can call on 40 years of experience. Can you imagine her Rolodex? She'd have contacts from around the world, and money coming in from around the world that would be a total game changer."

President Obama says she was a formidable opponent when she pushed him for the Democratic nomination in 2008.

"She was an outstanding Secretary of State, she is my friend, I think she would be an excellent President."

Commentators say the former First Lady will need to win over the so-called Obama coalition.

They're said to be black, and young educated white voters who supported Barack Obama in 2008 and 2012.

Greg Milam of Sky News says her run for the presidency will be a bruising battle.

"She will raise a billion dollars, the opponents will as well, and we know what they do with that money. The attack ads are vicious and they're everywhere, and that's what will happen for the next 18 months. The Clintons are polarising figures. She's very popular of course with a lot of people but a lot of people don't like the Clintons and will never vote for them."

The race for the White House could again see the Bush and Clinton political dynasties pitched against each other.

Jeb Bush, younger brother of George W, is believed to be just weeks away from putting his hat in the ring for the Republicans.

Jack Tame says Bush has the means to be a real challenger to the Clinton campaign.

"Certainly Jeb Bush would be able to raise money that would compete with Hillary Clinton. So it's very possible, 19 months out there is a long way to go, that we could see a Clinton/Bush contest for President."

CNN's Mark Preston says both Clinton and likely republican candidate Jeb Bush are making sure their message is about them, rather than their family political history.

"Hillary Clinton today, in that video, did not show Bill Clinton at all. There was no mention of Bill Clinton. In fact he has said that he will take a backseat in this campaign, at least initially."

Tainted by email scandal

Hillary Clinton's email saga could affect her presidential campaign.

Iona College Political Scientist Jeanne Zaino says Hillary Clinton's use of a private email account and then deleting messages has worried voters.

She says though she's a strong candidate, it could hamper her chances.

"The latest polls show that people are very worried that Hillary Clinton is not honest or trustworthy, and the email issue is shocking to some people. I can't say how this is going to play out."