A new advertisement ahead of Tuesday's presidential election shackles Mr McCain to Mr Cheney and the unpopular legacy of President George W. Bush, and also questions the qualifications of his Republican running mate Sarah Palin.
The ad mentions that Democrat Obama has been endorsed by respected figures like billionaire Warren Buffett and former Republican secretary of state Colin Powell, then cuts to footage of Mr Cheney at an event in Wyoming Saturday.
'I'm delighted to support John McCain ... and I'm pleased that he's chosen a running mate with executive talent, toughness and common sense, our next vice president Sarah Palin,' Mr Cheney said.
The announcer then says 'boy did McCain earn it, he voted with Bush and Cheney 90 per cent of the time,' before the ad closes with a picture of a smiling Mr Bush and Mr McCain standing arm in arm.
Mr McCain has tried for months to escape from the heavy shadow cast by the Bush administration as a crisis ravages the economy, so some analysts saw the timing of Mr Cheney's remarks with the election looming on Tuesday as puzzling.
It was not the first time that the vice president had spoken of his support for the Arizona senator, but came at a time when President George W. Bush seems to be avoiding the spotlight to avoid damaging Mr McCain.
In June, a Harris poll found that only 18 percent of Americans thought Mr Cheney was doing a excellent of pretty good job. A Fox poll last month found 29 per cent of those asked approved of Mr Bush's job performance.
Mr Obama personally mocked Mr McCain over Mr Cheney's support on the campaign trail on Saturday.
'Earlier today Dick Cheney came out of his undisclosed location and he hit the campaign trail,' Mr Obama told a rally in Pueblo, Colorado, on Saturday.
'So I would like to congratulate Senator McCain on this endorsement, because he really earned it. That endorsement didn't come easy. Senator McCain had to vote with George Bush 90 per cent of the time and agree with Dick Cheney to get it,' Mr Obama said.
'McCain had to serve as Washington's biggest cheerleader for going to war in Iraq and support its economic policies that are no different from the last eight years.'
'Do you think Dick Cheney is delighted to support John McCain because he thinks John McCain is going to bring change to Washington? Do you think John McCain and Dick Cheney have been talking about how to really shake things up?' he asked.
At a campaign event in Laramie, Wyoming, Mr Cheney hailed the 72-year-old Vietnam veteran as 'the right leader for this moment in history'. Mr Cheney brought up the September 11, 2001 attacks, which he said 'left our country shaken that day', and highlighted Mr Bush's role as commander-in-chief.
'In that terrible time we looked to our leader, and we found new strength. In the aftermath of 9/11, few would have guessed that our nation would go this long without another attack, but we have,' he said to applause from the crowd.
'John is a man who understands the danger facing America, he's a man who has looked into the face of evil and not flinched,' said Mr Cheney, who has served as vice president alongside President George W. Bush for two terms. -- AFP