Former President Barack Obama claimed responsibility for the booming economy and launched a scathing attack on Donald Trump as a threat to democracy.

The 44th US president also branded his successor a 'demagogue' who was part of the culture of 'celebrating bullies'.

Speaking to a crowd of thousands in a school auditorium in Cleveland, Ohio, yesterday, Obama lashed out at Trump's tax cuts for 'the most wealthy and powerful' and said the policy would damage the economy in the long run.

While backing Ohio's Democratic governor nominee Richard Cordray, the former commander-in-chief claimed responsibility for the current state of the US economy and said the upturn in growth started on his watch.

Walking on stage to U2's City of Blinding Lights, Obama pleaded with the audience, 'we have a chance to restore some sanity to our politics...because you are the only check on bad policy'.

Trump has repeatedly made record low unemployment and the strong American economy the centerpiece of his administration.

Obama claimed responsibility for the booming economy and attacked the culture of 'celebrity bullies' that was damaging democracy during his speech in Ohio yesterday

Obama smiled as the crowd cheered for him during his stop in Cleveland. The rally was a part of the Democratic effort to take control of office for their party, which is out of power at every level of Ohio government

On Monday he tweeted: 'The Economy is soooo good, perhaps the best in our country's history.'

But to a cheering crowd last night, Obama slammed Trump's economic policy and said the boom began under his presidency adding, 'just remember when it started'.

He also criticized Trump for his subsidy for 'corporate polluters' with a hand out of '1.5 trillion dollars in tax credits', that would have to be fixed by 'a Democrat like me coming back in'.

Obama also declared that Americans are 'supposed to stand up to bullies, not follow them' and railed against the 'post-truth' era.

He said: 'Some things are complicated, when I was president I was confident the American people wanted the truth.

'When there's a vacuum in our democracy, when we don't vote, when we take our basic rights for granted - other voices fill the void and demagogues who promise simple fixes to complicated problems.'

The former president said Republican control of Washington would threaten Medicaid, affordable health care and even democracy.

Former President Barack Obama rallied a crowd of thousands during a speech on Thursday evening delivered in Cleveland Ohio, marking his third stop on his campaign trail

Obama also slammed 'opportunists' who undermine democratic institutions by exploiting divisions in society for political gain.

He also said the current administration makes it harder for 'minorities, young people and poor folks' to vote.

Although he didn't blast President Donald Trump by name, he slammed the current administration saying: 'This is not normal what we're seeing. It is radical.'

He said: 'Even the folks who won don't seem happy. Have you noticed that?

'The Republicans won the House, they won the Senate. They're still mad, which is interesting. So just remember when you hear about these folks bragging about this economic period, just remember when it started, he added.

Obama said Republicans, 'appeal to our tribal instincts. They appeal to fear. They try to pit one against another.

The president called the Trump administration 'not normal' and urged the crowd to vote the midterm elections

Still got it! Obama stopped for selfies and handshakes with fans that gathered around him

'They try and say border security, 'we'll keep out those folks who don't look like us or sound like us'.

'That's a playbook as old as time. In a healthy democracy, that playbook doesn't work.'

He also warned against voter indifference, saying it was the biggest threat to democracy, adding, 'if you don't like the direction of the country, you can't just get angry.

'You can't just mutter to yourself while you're watching TV. You can't just move. You've got to vote'.

Cordray, who previously worked as his Consumer Financial Protection Bureau director, Obama called 'my friend', faces Republican Attorney General Mike DeWine in one of the season's most closely watched governor's races.

Former president Obama said Americans are 'supposed to stand up to bullies, not follow them' when he address a crowd at a rally for Democrat candidate Richard Cordray

During his speech he backed Ohio's Democratic governor nominee Richard Cordray, pictured right, who he called 'my friend'. Cordray worked as the Consumer Financial Protection Bureau during the Obama administration

'You will read quotes from Republicans saying, 'Wow, this is messed up.' Well, why aren't you doing something about it? 'Well, we can't, because we really like these tax cuts for the wealthy. … So we'll put up with crazy,'' he said during his speech.

Democrats hope to seize back control of the office in Ohio for their party, which is out of power at every level of Ohio government, and take Republican Governor John Kasich's seat.

Obama also appeared with US Senator Sherrod Brown who faces a challenge from Republican Jim Renacci, a congressman from Wadsworth.

The appearance is part of a swing across the country by Obama to boost Democrats' efforts to win House seats and state elections.

Ohio marked Obama's third campaign stop following speeches in Anaheim, California and Urbana, Illinois.

He's been crisscrossing the nation urging voters to head to the polling stations, particularly spending time in red areas.