As we enter the final days of the 2012 presidential campaign, let’s take a moment to consider a quality that Americans have valued in our leaders since the birth of our great nation: Integrity.

President George Washington summed up the importance of integrity when he wrote that “the character of an honest man” is “the most enviable of all titles.”

Our greatest president, Abraham Lincoln, likewise drew strength from his honest character. “I have never tried to conceal my opinions, nor tried to deceive anyone in reference to them,” the Great Emancipator wrote. “I am glad of all the support I can get anywhere, if I can get it without practicing any deception to obtain it.”

Sadly, we have come a long way from the high standards of Washington and Lincoln.

In Mitt Romney, Americans have a candidate who refuses to tell the truth because it might get in the way of his ambition. Many politicians modify their views in the course of their careers. But what Mitt Romney does is far different.

In the course of the last month, for example, he changed his public stance on so many issues that attentive voters are right to question whether he is motivated by anything other than his relentless desire to sit in the Oval Office:

  • He once opposed “moving heaven and earth” to find Osama bin Laden. Now, he claims he always backed that goal.
  • He ran for the GOP nomination calling for tax cuts, even for the top 1 percent. Now, he says the rich won’t see a tax cut.
  • He claimed to support the Blount Amendment which eased women’s access to contraception. Now he says he opposes the whole idea.

Romney says he worked in a bipartisan way when he was governor of Massachusetts, but fails to mention that he vetoed more than 800 bills. He says he loves teachers, but just a month ago claimed that hiring more teachers was a mistake. He also claims he turned around the Salt Lake Olympics, but never mentions the $2.7 billion taxpayers paid to cover the deficit he left behind. He said he supported government help for the automobile industry while they went through the bankruptcy process, but at the time of the rescue, he said if President Obama’s plan went through “you can kiss the American automotive industry goodbye.”

And then there is the now-infamous tape in which, behind closed doors, he disparages 47 percent of the country, including senior citizens, veterans and college students. Onstage now, in front of the network cameras, he says he is deeply concerned about all Americans.

Here’s the logical conclusion one draws from watching Mitt Romney run for President: He changes positions repeatedly and without shame. When confronted with past positions, he simply denies them. He seems constitutionally incapable of being honest about himself, his record and the proposals he supports.

That’s why voters should not be asked to take it on faith that he hasn’t cheated on his taxes or that he’s come up with a way to pay for his budget plan without slashing indispensable programs such as Social Security, Medicare or Medicaid. For Romney, this is the Big Con.

By contrast, America now has a President who believes we need to pull together to find real solutions for the challenges we face. President Obama took bold action to keep America from descending into a second Great Depression. He saved millions of jobs, enacted historic health care reform to protect America’s families from predatory insurance companies and won approval for the toughest Wall Street regulation since the 1930s. He ended the Iraq War and “Don’t Ask, Don’t Tell.” Even now, he is working to end our involvement in Afghanistan and use the savings to cut the deficit and create new jobs. He strongly supports rebuilding our infrastructure, investing in education and training, and protecting the middle class. He believes in America and trusts our people.

When asked earlier this year if he thought Romney was a liar, Newt Gingrich replied point blank: “Yes.” Gingrich said Romney was running for office as “a poll-driven, consultant-guided” candidate. Gingrich joins a long line of Republicans – from John McCain and Rudolph Giuliani, to Rick Santorum and Mike Huckabee – who have gone on record questioning Romney’s character.

At this stage of the campaign, with mere days before Election Day, it no longer even makes sense to try judging Romney’s candidacy by his views. He has too many irreconcilable differences with the truth for that – and it’s those differences that disqualify him from holding the highest elected office in the land.