The phrase "a consistent advocate" is correct and usable in written English.
You can use it to describe someone who regularly supports or promotes a particular cause or idea.
Example: "She has been a consistent advocate for environmental protection, tirelessly campaigning for sustainable practices in her community."
Alternatives: "a steadfast supporter" or "a loyal proponent."
Mr. Löning has been a consistent advocate of public diplomacy.
Ms. Norton has also been a consistent advocate of states' rights and minimal federal interference.
And Mr. Kerry defended himself as a consistent advocate of removing Mr. Hussein.
But he has also been a consistent advocate of integrating health and social care.
He also was a consistent advocate of closer European integration, centered on the euro currency area.
Throughout his long career, Du Bois was a consistent advocate for the study of African history and culture.
For Focus on the Family, the film was "so consistent with our strategic priorities to advocate for children and be a voice for life," Kelly Rosati, vice president of community outreach for the group, said, adding that with a story about adoption the film followed "what we would describe as a pro-life agenda, an agenda that values both moms and their preborn babies".
As a gubernatorial candidate, I was a vocal, consistent advocate for policies I believed best for Virginia — including closing the gun show loophole and strengthening background checks.
On global-warming policy, Obama has been a more consistent advocate of action, but after his comprehensive climate-change legislation died in Congress, in 2010, his E.P.A. was slow to fill the policy vacuum with its new regulatory regime.
The former State Department official added: "I believe I can make the strongest contribution to our future by continuing as a clear and consistent advocate for a strong Reaganite foreign policy that values peace through strength".
