Raju was born on 18 November 1954 in Poonthura, Trivandrum to S Alphonse and T Lourdamma in a poor family from the fisher community.

[5] Raju was the unit president of Kerala Students' Congress (KSC), the students' wing of Kerala Congress, in St Xavier's College, Thumba, and Mar Ivanios College, Thiruvananthapuram.

But in the 2021 elections, he defeated VS Sivakumar by more than 8000 votes.The coastal region has been Raju's support base.

His first attempt to reach the Assembly went in vain as he lost to M M Hassan of the Congress in Thiruvananthapuram West in 1991.

In November 2024, in a legal setback, supreme court allowed criminal proceedings against Raju in the tampering evidence case, dating back to the early 1990s.