"We have eleven million good people who need a good shot," Biden said Wednesday during a coffee shop photo-op with Udall and Denver Mayor Michael Hancock.
"Now is the time to act. The one request I have is keep up the drum beat on these guys. I believe in immigration reform with all I have."
Later in the day Biden hosted a private fundraiser for Udall, a move that drew criticism from Republican party officials who feel the senator is too chummy with the White House.
"It's no surprise that after supporting President Obama 99 percent of the time that Mark Udall's being rewarded with a closed-door fundraiser with the Vice President," said RNC spokesperson Michael Short.
"Obstruction of the Keystone pipeline are paying dividends for his campaign account, Coloradans are the ones having to live with cancelled insurance plans, Medicare cuts and unrealized jobs."