Sentence:  Just as Mr. Clinton began a comeback with a down-home plea for forgiveness, Mrs. Clinton now seems determined to prove, perhaps to the point of overcompensation, that she will not repeat the mistakes that <WSD>plagued</WSD> her 2008 campaign. 
Meaning of the word marked with <WSD> tags:  To harass, pester or annoy someone persistently or incessantly.