DENVER -- Public officials are navigating ethical pitfalls as they hop from party to party during the Democratic National Convention.

During a welcoming party Sunday night, top officials stuck to water instead of sampling the free booze and hors’dourves at a party hosted by top lobbying firm Brownstein, Hyatt, Farber, Schreck.

“Well, for my sake, I'm drinking bottled water out of my trooper's car ... we're very careful about it,” said Gov. Bill Ritter as he walked into the Brownstein bash at the Denver Art Museum.

“So does it make it difficult for you?” asked CALL7 Investigator Tony Kovaleski.

"No, it does not, because we just draw a pretty clear line and it's easy to stay on the side of the line, Tony," Ritter said.

Jane Feldman, executive director of the state Independent Ethics Commission, said state officials have to be very careful if they’re going to a party hosted by lobbyists.

Kovaleski asked: “Big party hosted by a lobbyist firm, you walk in, you eat, you drink, you get a gift and you walk out. Ok or not ok?”

“Well, I don't really want to get into hypotheticals, but probably not ok. You know, unless it's finger food and its worth, well, if it's a lobbyist and you know it's a lobbyist then, you probably shouldn't go,” Feldman said.

U.S. Rep. Mark Udall, who is running for U.S. Senate from Colorado, didn’t bring his own water but said that’s what he was drinking at the party. He is covered by a federal law instead of Amendment 41, which deals with state officials and employees.

"I just had a glass of water and visited with as many people as I could," Udall said as he left the party.

“Any concerns about breaking any federal ethics rules by attending this?” Kovaleski asked.

"It's clear that the rules are being followed and people are transparent, above board and it's the way it should be,” Udall said.

Party organizers allowed reporters in but they didn’t want cameras documenting what was happening inside.

“Are we able to go in -- we're with 7News,” Kovaleski asked.

"No cameras inside but you can go inside,” said the attendant at the door.

“No cameras -- any reason why,” Kovaleski asked.

“That's what the people organizing the party decided to do,” she said.

The party was vetted through a federal ethics commission, lobby firm officials said. And Steven Farber, president and one of the firm’s founders, said it’s up to the politicians to make sure they don’t run afoul of any ethics laws.

“I believe if I were an elected official I would be monitoring it myself,” he said. “If I were a Congressman or a Senator-- I would be watching those things so they are not violated.”