In short, they first perverted the protectionist system until it ceased to be a national policy; and then compromised it until it ceased to be any policy at all.
Perhaps the Whigs failed and blundered most completely in the fight which they made against the Federal executive and in the interest of the Federal legislature.

They were forced into this position, because for many years the Democrats, impersonated by Jackson, occupied the Presidential chair, while the Whigs controlled one or both of the Congressional bodies; but the attitude of the two opposing parties in respect to the issue corresponded to an essential difference of organization and personnel.

The Whigs were led by a group of brilliant orators and lawyers, while the Democrats were dominated by one powerful man, who held the Presidential office.

Consequently the Whigs proclaimed a Constitutional doctrine which practically amounted to Congressional omnipotence, and for many years assailed Jackson as a military dictator who was undermining the representative institutions of his country.

The American people, however, appraised these fulminations at their true value.