Glenn Greenwald, who famously worked with Edward Snowden this year to publicize the NSA's massive surveillance program, today rejected the idea that his role in the Snowden affair has gone from journalist to cheerleader, calling that criticism "ludicrous" and questioning his MSNBC interviewer's own partisanship.

In a chat with MSNBC's Kristen Welker, Greenwald used Welker's own network to scoff at the question, "What do you say to your critics who say that you've become more of a spokesman for Edward Snowden?"

We're on MSNBC now, where close to 24 hours a day, the agenda of President Obama and the Democratic Party are promoted, defended, glorified—the agenda of the Republican Party is undermined. That doesn't mean that the people who appear on MSNBC aren't journalists; they are. I think every journalist has a viewpoint. My viewpoint is very clear. I don't hide it. It's that I think what Edward Snowden did is very admirable and heroic. But at the same time, the ultimate test of a journalist is "Is what you publish accurate and reliable?" And I think, with regard to every story that we've published over the last six months, there hasn't been a single correction made to any of them. Very few have been called into question. And I think that's the ultimate question when it comes to "Is this journalism?"

"Well, I think the point is not so much about MSNBC and what happens here but more that sometimes when you talk about Edward Snowden you do defend him, and some people wonder if that crosses a line," Welker said.

"Sure, I do defend him, just like people on MSNBC defend President Obama and his officials and Democratic Party leaders 24 hours a day," Greenwald responded.

"Not everyone on MSNBC does that 24 hours a day," Welker said.

"No, not everybody, but a lot of people on MSNBC do," Greenwald said.

Snowden, who yesterday delivered Channel 4 UK's "Alternative Christmas Message," remains in asylum in Russia.