[1] He operated on the left of the ARP and he advocated increased government interference in the economy and the extension of suffrage.
In the 1901 general election, Staalman was re-elected to the House of Representatives on an Anti-Revolutionary ticket, but he was dissatisfied by the party's conservative course.
In the 1917 general election, Staalman was narrowly defeated by Pieter Oud in the Den Helder seat.
In the 1922 general election, the threshold to enter parliament was raised, and the CDP was unable to maintain its seat.
It had a traditional left-wing programme, involving the extension of suffrage to all householders, the implementation of mandatory insurance against sickness and invalidity (an early form of the welfare state), progressive taxation and stronger rights for workers.