Watch the video above, and try not to cringe. It's Jon Keyser, Republicans' preferred candidate to challenge Sen. Michael Bennet (D) in the Colorado Senate race, having what can be charitably described as a brain freeze — or, less charitably, a Marco Rubio moment. And it isn't good news for Senate Republicans hoping to unseat Bennet in a race that could help them keep the Senate.

At a GOP Senate forum Thursday, Fox 31 moderator Joe St. George asks Keyser about a Denver7 report (see below) that at least 10 signatures to get Keyser on the GOP's June primary ballot were forged. A Denver7 investigative reporter, Marshall Zelinger, said he noticed some of the signatures on Keyser's ballot looked suspiciously like that of one of the campaign's hired signature collectors, so he checked it out. This is what he found:

The story had been out for two days by the time Keyser appeared at Thursday's GOP forum. It was a big story in Colorado politics and pretty much a given the candidate would be asked about it.

But Keyser didn't seem to have a solid answer. Four times, St. George asks Keyser about whether he knew the signatures were forged. Four times he deflects by repeating a version of the same line: I'm on the ballot, and I'm going to beat Michael Bennet. (Keyser almost didn't make the ballot after Colorado's secretary of state called into question 86 signatures.)

It was an awkward moment at best and probably doesn't instill much confidence in Keyser's prospects. Procedural ballot questions in front of a Republican-leaning audience will be the least of Keyser's worries when he's in a hard-fought general election against the better-funded, more-practiced Bennet.

But that video arguably isn't even the worst of it. In an interview with Denver7's Zelinger during a lunch break, Keyser was asked eight more times about the signatures in question, and eight more times he repeated his talking point.

Then things got weird. In a flash of recognition, Keyser asks the reporter -- whose first name he keeps messing up -- whether he was the one who "was creeping around my house yesterday?" The reporter confirms he knocked on Keyser's door. Keyser says the reporter woke his kids up and then asks, "Did you get to meet my dog?" He then mentions how big and protective his dog -- apparently a 165 pound Great Dane -- is, to which Zelinger replies: "I don't know what that meant, but okay."

Keyser wraps up the painful exchange by saying: "He's a great dog." Then he goes back to his talking points, which by now is something he's clearly memorized since Zelinger broke the story two days earlier. It's an odd moment between reporter and politician, which you can watch here:

RAW VIDEO with Jon Keyser. FULL DISCLOSURE: What I have done to get information and answers about my forged signature investigation involves "door knocks." If you disagree, I understand. Here is my timeline: TUESDAY: I went to the home of Maureen, the signature collector in question, on Tuesday morning, before the story aired. I was told she no longer lives there. I contacted the Keyser campaign on Tuesday, hours before the story aired. I received no response. I even reached out to the state GOP for help. The chairman was aware of my attempts to reach the Keyser campaign. TUESDAY NIGHT: On Tuesday night between the 6p and 10p stories, I contacted the campaign again. No response. WEDNESDAY: I went to the home of the man who runs the company that hired the signature collector. I met his wife, she was lovely and said she would let him know I came by. I left him a voicemail. I received no response. On Wednesday, I went to the offices listed on the Federal Election Commission documents submitted by Keyser when he submitted his affidavit to become a candidate. One was a UPS Store, the other was a fundraising company. I then went to his home in the afternoon and rang the doorbell. I met his nanny and dog. I apologized to the nanny when she told me she was a nanny because I figured that meant I just woke up a child. Wednesday night, I contacted the campaign again and received no response. THURSDAY: This is what happened...

Posted by Marshall Zelinger 9News on Thursday, May 12, 2016

In an interview with The Fix, Zelinger said he tried to contact Keyser's campaign several times before and after his story ran to get a response about the signatures, but to no avail. So he met Keyser at this forum and asked him,  but then quickly became part of the story himself.

"This story is not about 'Hahaha look what I found,' Zelinger said. "It's: These voters told me their signatures were forged. What can you tell them about what you know about this. I guess I gave up trying to get that, because I knew I wasn't going to, because at some point it's going to be badgering."

Now, instead of signatures, the story in Colorado political circles has become Keyser and Zelinger's stand off about a dog. Zelinger said he released the raw footage to be transparent about his interview.

Here's why we're bringing this to your attention. Not even two weeks ago, we asked whether Republicans were blowing their chance to unseat Bennet, who is Senate Democrats' most vulnerable incumbent and one of Republicans' best pick-up opportunities in a year they're largely playing defense. But things hadn't gone so smoothly for Republicans in Colorado. Recruiting problems. Ballot problems. A chaotic primary with no clear front-runner.

Republicans were optimistic. At last they got their candidate who was going to clear the field: Keyser, a 34-year-old combat veteran who is strong where they think Bennet is weak. And within the week, Keyser's ballot question was solved. He would be on the ballot. They could move on from these embarrassing missteps and focus on taking down Bennet.

Judging by Keyser's performance Thursday, it seems like they have some more work to do before that can happen.