been this 42 years total in washington, d.c. and we understand the change sometimes is necessary. reporter: this is the tea pa party s best chance. chris mcdaniels. many feel like strangers in this land. a new america rise to go take its place. we recoil from that. reporter: he is challenging 76-year-old thad cochran who arrived in congress the year america pulled out of vietnam. i never, in a million years, thought i would challenge senator cochran. he has been there as long as i ve been alive. when he went to washington in 1973 the debt was only about 400 billion. did you know that? we stare today 42 years later and give or take it s $17.3 trillion. reporter: do you think senator cochran is ready for a campaign like this? i don t know. i hope so.