The phrase "rightful cause" is correct and usable in written English.
You can use it to refer to an action or situation that is based on appropriate or justified reasons. For example, "The protesters marched on the capital to fight for their rightful cause - equal rights for all citizens."
Some members of both communities will see this war not as waste but as a rightful struggle in their cause; others might view with distaste the spectacle of a "monument" which places victim and killer, paramilitary members and unborn child, within the same literary monument.
The war continued for a few years without a decision until the revolt of Bahram Chobin caused the rightful Persian shah, Khosrau II (r. 590 628), to find refuge in Byzantine territory.
My family discriminated against me and denied me my rightful property rights.
It puts credit derivatives in their rightful position as the ultimate cause of the financial crisis -- not the selling of houses to poor people, not super-low Federal Reserve interest rates, not a surplus of savings from China or Japan.
Rather, the desperation of millions... millions of those with nowhere to go, risking the whims of the ocean because they have no other choice... seems to have taken its rightful place in our priority of causes list.
When the rightful owners return they drive off again.
Under the socialism favoured by Marx, the surplus product of labour, previously appropriated by the capitalists, would be returned to its rightful owners, the workers, thereby eliminating the cause of poverty.
At best, Stephen O'Smith is a rightful opposer of the EDL's fascist cause, who's found a slightly misguided way of expressing it, given the tensions mounting between the far right and those who oppose them in this country.
However, legally speaking, if Whitney were a rightful co-founder who was stripped of that title without reason or cause, then Tinder could be in for a world of hurt.
