DENVER - U.S. Senator and former presidential candidate John Kerry appeared before the California Democratic Party delegation Wednesday to hammer home the differences between a potential Barack Obama administration and one led by Republican John McCain.

"Let me tell you about the great differences between Barack and John McCain. Barack announced his vice president on the Internet and John McCain is planning to use the Pony Express," Kerry (D-Massachusetts) said to laughs amongst the 1,000-plus ballroom audience.

"Seriously though, Americans are looking for judgment and increased security. I can tell you without a doubt that we are less safe now than we were when George Bush became president. With the Republicans we are going backwards, not forward," Kerry said.

The senator said that important national issues such as healthcare, the war in Iraq and expected appointments to the Supreme Court are in balance come November.

"Listen folks we can win this election - we must win this election," Kerry entreated

Kerry joined Senators Claire McCaskill (D-Missouri) and Barbara Boxer (D-Calif.) in delivering short, 10- or 15-minute-long speeches to the California Democrats Wednesday morning.