The story of Senator Edmund G. Ross is a well-known story of the power of a deciding vote in American history. Ross held the vote that acquitted President Andrew Johnson from removal of office, initiated because of his unpopular Reconstruction policies.

John F. Kennedy chronicled the story in his Profiles of Courage, published in 1957 before his presidency while recovering from back surgery.

While Ross was one of seven to 'defect' from the Republican-led impeachment, he was really only one vote in 54, with 19 others also voting for acquittal.

With any of the 19 votes essential for acquittal, why does history remember Ross as the deciding vote?

The answer is very simple and should be a lesson to us today on the power of the vote: Ross hadn't made up his mind until it was time to actually vote.

As far as the Republican Party was concerned, Johnson was guilty long before the first votes were cast to impeach in the House of Representatives.

The Democrats, while considerably outnumbered, were in lock-step for acquittal.

But Ross' vote was special; he hadn't fully decided either way and refused to be bullied or bribed into a decision either way.

So frustrated was Ross by his own party that in his 1896 book, the History of the Impeachment of Andrew Johnson, he devoted an entire chapter to his thoughts on 'Was It A Partisan Prosecution?' His belief in the overall atmosphere was not unlike today's bitter partisanship:

To sum up this feature of the proceeding--the Republican majority of the Senate placed themselves and their party in the attitude of prosecutors in the case--instead of judges sworn to give the President an impartial trial and judgment that their course had the appearance, at least, of a conspiracy to evict the President for purely partisan purposes, regardless of testimony or the facts of the case-that public animosity against Mr. Johnson had been manufactured throughout the North by wild and vicious misrepresentations for partisan effect--that practically the entire Republican Party machinery throughout the country was bent to the work of prosecution. The party cry was "Crucify him!" "Convict him anyway, and try him afterwards!" With rare exceptions, the Republican Party of the country, press and people, were a unit in this insensate cry. They were ready to strike, but not to hear.  -- Edmund Ross, Chapter 12

Over a century later, this level of antics has become the norm in our congressional proceedings -- the constant threat of impeachment if the executive doesn't bend to the will of the legislative branch.

But while this is a good history lesson, the moral of this story is essential for all voters: the voter who refuses to make a decision until all the facts are plainly established is the most powerful voter in the country.

The political parties spend millions of dollars trying to sway the undecided vote, often the breeding grounds of broken campaign promises from straying too far from party ideals. The 'party faithful' are already in the back pocket of the political machine -- while valuable votes, they definitely are not the ones that "win" elections.

The lesson for each of us is that we should be willing to carefully weigh the facts of each vote that is placed before us, to vote based on the best choice, and ignore the temptation to be a party-line voter.

When we do this, we are the most powerful voters in America -- the ones the political parties actually have to work for to win.