White said Perry, who's been governor for a decade, has run his office as a "political machine" and a "revolving door" for lobbyists.
Glass said the temporary new state franchise tax is not doing enough to help small businesses.
Perry has refused to appear with White until the Democratic candidate makes public more of his tax returns.
Perry spokesman Mark Miner said the ex-Houston mayor continues a campaign based on personal attacks.
About 300 people attended the League of Women Voters event.