2001-Present

Drilon ran again for the Senate as independent but was under the People Power Coalition senatorial line-up. The lineup was carefully chosen and the first letter of the candidate's surname (except for Roberto Pagdanganan) ended up with the line VOT FOR D CHAMMP. The line became a hit, and it led to the election of most of the coalition's senatorial candidates including Drilon.

When the session resumes July 2001, Pimentel was replaced by Drilon as Senate President. Pimentel bolted the administration coalition and joined forces with the opposition coalition. In 2003, Administration coalition partner Liberal Party, to which Arroyo's father, Diosdado Macapagal served as chairman in the 60's, invited Drilon to be its member. Days after, Drilon was elected chairman of the political party. Before the 2004 elections, Drilon invited Senator Rodolfo Biazon as its member. Biazon bolted Raul Roco's coalition Alyansa ng Pag-asa just days after he joined convention as its new member.

Drilon had close contacts with President Gloria Macapagal Arroyo since 2001 and actively supporting her when she ran for a fresh mandate to the presidency. That relationship ended in July 8 when Drilon together with Biazon and some prominent members of the Liberal Party decided to withdraw support from her and asked for her resignation. In Arroyo's 2005 State of the Nation Address, Drilon was only one noticed not applausing in entire program.

Drilon raised the issue of an overprized Chinese railway system to be built north of Metro Manila. He promised that he would be a fiscalizer rather than an ally of the President.