Not since Bill Clinton challenged the definition of "is" has so much hinged on a very short word.
John Edwards appears to basing much of his defense, which begins today in a North Carolina courtroom, on the legal interpretation of the word "the."
Edwards has listened to three weeks of testimony meant to prove that he violated federal campaign finance laws by using nearly $1million in donations to hide his mistress Rielle Hunter and her pregnancy during his bid for the 2008 presidential election and in the months after he dropped out -- but was still angling to be vice president or attorney general.
If convicted Edwards could be sentenced to 30 years in prison.
The statute governing illegal receipt of campaign contributions "means any gift, subscription, loan, advance, or deposit of money... for the purpose of influencing any election for federal office."
The words "the purpose" suggests that in order for a conviction, the sole reason for the money would have to be to finance a presidential campaign.
Edwards' legal team has argued he did not know it might be illegal, did not intend to break the law and that his main reason for hiding Hunter was to keep her secret from his wife, Elizabeth, who was dying of breast cancer.
Prosecutors, however, are arguing the law should be interpreted to mean "a purpose," meaning use of the donations does not have to be solely for a political campaign.
"It is sufficient under the law if you find that the gift, purchase, or payment was made for, among other purposes, the purpose of influencing any election for federal office," prosecutors argued in court filings last week.
Edwards' lawyer Abbe Lowell has argued that prosecutors are asking the jury to "invent a new crime" with its interpretation of the law.
Edwards' legal team will begin its defense today, which is expected to last a week. He may have a lot to overcome. Prosecutors concluded their case last week by showing an interview Edwards gave to ABC News' "Nightline" program in which he clearly lied several times, including denying that he had fathered Hunter's baby.
Judge Catherine Eagles also rejected a motion by Edwards' team to dismiss the charges against him.
The defense is expected to go after the prosecution's key witness Andrew Young, a former Edwards' aide who helped hide Hunter, going on the road with her to keep her away from the press, even claiming paternity for his boss.
Edwards defense has argued that much of the money was solicited by Young and he used the scandal to enrich himself.
Among Edwards' witnesses will likely be his daughter Cate, who has been his most visible supporter throughout the trial.
Hunter is on Edwards' list of witnesses, but it's not clear whether she will be called. Her presence in the courtroom could be volatile.
It's not yet known whether Edwards will take the stand in his own defense.