If oil plunges into the mid-$20s, that could arouse more vigorous opposition.

The toxin of xenophobia needs vigorous opposition and hostility.

The first column, however, faced more vigorous opposition on the right of the front.

In this undertaking he met with vigorous opposition.

They met vigorous opposition to their ideas from senior army officers who favored the use of armor in support of infantry and not as a separate arm conducting independent operations.