DENVER—Democratic women brushed off a new ad by Republican John McCain that Democrat Barack Obama didn’t pick Hillary Rodham Clinton as a running mate because of their hard-fought primary race

“Good try—but not good enough,” said House Speaker Nancy Pelosi, appearing with three other female Democratic elected officials on the eve of the party convention.

Though Clinton didn’t appear, Pelosi and Kansas Gov. Kathleen Sebelius, herself a vice presidential candidate, doused speculation that the lack of a female on the Democratic ticket could hurt Obama.

“There is so much more in common with Hillary Clinton and Barack Obama than with John McCain,” Sebelius said.

The McCain ad airing Sunday shows Clinton during the primary battle saying critical things about Obama. A voiceover announcer then says, “She won millions of votes but isn’t on the ticket. Why? For speaking the truth.”

Pelosi praised Obama’s pick, Delaware Sen. Joe Biden, and said she doubted any Clinton supporters would be swayed by the McCain ad.

“Women have the most to gain with the election of Barack Obama, and the most to lose with the election of John McCain,” Pelosi said.

Clinton will repeat her endorsement of Obama in a prime-time speech Tuesday. Party leaders will be watching to see whether she and former President Bill Clinton heal any remaining divisions in the party.

Hours before Hillary Clinton’s speech, a group of supporters called 18 Million Voices were to march through downtown Denver. But on fliers promoting the march, organizers say the event will be a celebration of Clinton’s campaign and not a protest of Obama’s vice presidential choice.