Barack Obama’s speech to 75,000 people gathered in Denver set the tone for the final months of electioneering.

A journey that began in earnest in January is moving into its last and most exhilarating period.

Accepting the Democratic nomination for President of the United States “with profound gratitude and great humility,” the first African-American to do so from either party, Senator Obama praised his opponent in the primaries, Hillary Clinton, and sent a strong message to the American people about his progressive values.

“We meet at one of those defining moments – a moment when our nation is at war, our economy is in turmoil, and the American promise has been threatened once more,” he said.

Attacking the “failed policies” of President Bush, the 47-year-old junior Senator from Illinois said America “is a better country than this.

“We are more compassionate than a government that lets veterans sleep on our streets and families slide into poverty; that sits on its hands while a major American city drowns before our eyes.”

Obama, often criticised for his crowd-pleasing, inoffensive rhetoric about hope and change, gave a tantalising glimpse of what we can expect in the Presidential debates later in the campaign, with some wounding attacks on his Republican opponent.

“It’s not because John McCain doesn’t care. It’s because John McCain doesn’t get it,” he said.

“For over two decades, he’s subscribed to that old, discredited Republican philosophy – give more and more to those with the most and hope that prosperity trickles down to everyone else. In Washington, they call this the Ownership Society, but what it really means is – you’re on your own.

“Out of work? Tough luck. No health care? The market will fix it. Born into poverty? Pull yourself up by your own bootstraps – even if you don’t have boots. You’re on your own.

“Well it’s time for them to own their failure. It’s time for us to change America.”

Obama also set out some solid tax and policy positions.

“Change means a tax code that doesn’t reward the lobbyists who wrote it, but the American workers and small businesses who deserve it.

“Unlike John McCain, I will stop giving tax breaks to corporations that ship jobs overseas, and I will start giving them to companies that create good jobs right here in America.

“I will eliminate capital gains taxes for the small businesses and the start-ups that will create the high-wage, high-tech jobs of tomorrow.

“I will cut taxes – cut taxes – for 95% of all working families. Because in an economy like this, the last thing we should do is raise taxes on the middle-class.

“And for the sake of our economy, our security, and the future of our planet, I will set a clear goal as President: in ten years, we will finally end our dependence on oil from the Middle East.

“Now is the time to end this addiction.”

He also tackled education – “I’ll recruit an army of new teachers, and pay them higher salaries and give them more support” and health care – “you’ll be able to get the same kind of coverage that members of Congress give themselves.”

The practical measures set out will go some way to satisfy critics who claim he lacks policies.

He chose the examples of former Democrat leaders when speaking about Iraq.

“We are the party of Roosevelt. We are the party of Kennedy. So don’t tell me that Democrats won’t defend this country.

“As Commander-in-Chief, I will never hesitate to defend this nation, but I will only send our troops into harm’s way with a clear mission and a sacred commitment to give them the equipment they need in battle and the care and benefits they deserve when they come home.”

Senator Obama, who supports civil unions but not gay marriage, set his position out clearly towards the end of his speech.

“I know there are differences on same-sex marriage, but surely we can agree that our gay and lesbian brothers and sisters deserve to visit the person they love in the hospital and to live lives free of discrimination,” he said.

Yesterday was the 45th anniversary of Martin Luther King’s “I Have A Dream” speech.

At the end of his oration last night, Senator Obama sought to inspire similar passion.

“This country of ours has more wealth than any nation, but that’s not what makes us rich.

“We have the most powerful military on Earth, but that’s not what makes us strong.

“Our universities and our culture are the envy of the world, but that’s not what keeps the world coming to our shores.

“Instead, it is that American spirit – that American promise – that pushes us forward even when the path is uncertain; that binds us together in spite of our differences; that makes us fix our eye not on what is seen, but what is unseen, that better place around the bend.

“That promise is our greatest inheritance.

“It’s a promise I make to my daughters when I tuck them in at night, and a promise that you make to yours – a promise that has led immigrants to cross oceans and pioneers to travel west; a promise that led workers to picket lines, and women to reach for the ballot.

“And it is that promise that forty five years ago today, brought Americans from every corner of this land to stand together on a Mall in Washington, before Lincoln’s Memorial, and hear a young preacher from Georgia speak of his dream.

“The men and women who gathered there could’ve heard many things. They could’ve heard words of anger and discord. They could’ve been told to succumb to the fear and frustration of so many dreams deferred.

“But what the people heard instead – people of every creed and colour, from every walk of life – is that in America, our destiny is inextricably linked. That together, our dreams can be one.

“”We cannot walk alone,” the preacher cried. “And as we walk, we must make the pledge that we shall always march ahead. We cannot turn back.”

“America, we cannot turn back. Not with so much work to be done.

“Not with so many children to educate, and so many veterans to care for. Not with an economy to fix and cities to rebuild and farms to save.

“Not with so many families to protect and so many lives to mend. America, we cannot turn back. We cannot walk alone.

“At this moment, in this election, we must pledge once more to march into the future. Let us keep that promise – that American promise – and in the words of Scripture hold firmly, without wavering, to the hope that we confess.

“Thank you, God bless you, and God bless the United States of America.”