Complex sentence: During the 2003 expansion referendum, critics of the system (including Texans for True Mobility) criticized METRO for spending public funds for "educational advertisements" about the proposed system, which critics claimed promote the referendum.
Split into simpler sentences: During the 2003 expansion referendum, critics of the system, including Texans for True Mobility (TTM), questioned METRO's financial practices. METRO was criticized for spending public funds for "educational advertisements" about the proposed system, which were claimed by critics to promote the referendum.