Chester Stranczek has not been challenged for office since 1973.

They haven't been challenged since 1948, with the Henry Wallace progressive party.

He has not been seriously challenged since first winning in a special election in 1971.

The conservative "historic" movement holds to certain traditional positions that have been challenged since the 1950s.

But that rate has been challenged since November 2001, when the government stopped issuing the 30-year bond.

I have been challenged from the effects of polio since the age of one.

This picture has been challenged, and changed, since the 1970s by modern scientific research on Zen.

The problem of developing artificial intelligence that learns the way humans do has challenged researchers since at least the 1940s.

This record has yet to be challenged by the Bofia sisters since 2006.

This ordinance has been challenged and overturned since that time.