The philosophical figurehead of the DLP (although not its political leader) was BA ("Bob") Santamaria. By directing their preferences to the Liberal Party, the DLP played a key role in keeping Labor out of office in Australia from 1955 to 1972.
In 1974, Gough Whitlam offered the DLP leader, Senator Vincent Gair, the ambassadorship to Ireland, in the hope that his departure would make it easier for Labor to obtain a Senate majority in the forthcoming double dissolution election. Although Whitlam's ploy was foiled by Joh Bjelke-Petersen, it did have the effect of discrediting the DLP-- the party lost all five of its Senate seats and never recovered.
The DLP still exists and stands candidates, although it receives only a small number of votes; it has a website at . The unions which supported the DLP rejoined the ALP fold, while many of the voters who supported the party continue to fall within relatively influential swinging demographics.