The knives are out for Amy McGrath.

Rep. John Yarmuth, the only Democrat elected to federal office from Kentucky, hinted Thursday that McGrath, a Marine combat aviator, might not be the best candidate to take down Senate Majority Leader Mitch McConnell next year as a series of unforced errors have already buffeted her campaign in its first two days.

Yarmuth told the Louisville Courier-Journal that McGrath made a "pretty significant mistake" by indicating that she would have voted to confirm Brett Kavanuagh to the Supreme Court on Wednesday. McGrath, who said she opposed Kavanaugh at the time of his contentious confirmation fight, flip-flopped four hours later on social media and said that after "reflection," she would have voted against Kavanaugh.

Yarmuth told the paper that the first days of McGrath's campaign "could have gone smoother," despite raising a whopping $2.5 million in its first 24 hours prior to hitting turbulence. By the end of the third day of her campaign on Thursday, McGrath had tallied over $3.5 million.

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"By her own admission she made a pretty significant mistake and corrected it," the lawmaker said. "I hope she prepares a little bit better for the rest of the campaign. I'm sure she will."

“I think a primary might be helpful in this situation." — Kentucky Democrat Rep. John Yarmuth

"I think a primary might be helpful in this situation," Yarmuth added. "Because whoever is going to face off against Mitch McConnell really needs to get their game in shape. Certainly, Amy would be a favorite in any kind of primary, but I think it would help her and if somebody else could beat her they would have demonstrated their strength as well."

Kentucky sports radio host Matt Jones was among the most likely to jump into a primary to challenge McGrath. Speaking Thursday, he said McGrath had experienced key “hiccups," and indicated he was open to running and would decide "fairly soon."

He specifically faulted McGrath for appearing to have “authenticity problems."

“I think she has let the national Democratic Party and the consultants consult her to death. They have literally taken the personality out of her,” Jones said at a business summit. “I would say to Amy McGrath, be Amy McGrath. Because at the end of the day if you’re Amy McGrath and you lose, then you can look in the mirror and say look I did it. If you’re this person they created... you’re gonna lose and you’re gonna feel bad."

McGrath's campaign launch Tuesday was aided by a breathless NBC News report hours earlier that McConnell's distant ancestors owned slaves -- a revelation blunted by McConnell pointing out that President Barack Obama's ancestors did as well.

In another striking moment, an eager MSNBC anchor also urged McGrath to tell viewers how they could easily donate to her campaign online.

But McGrath, who ran unsuccessfully for the House last year, was quickly criticized for her claim in a televised interview earlier on Tuesday that President Trump's election was similar to the 9/11 terrorist attacks. Then she opened the floodgates in an interview with the Courier-Journal, Kentucky's highest-circulation newspaper.

"You know, I think that with Judge Kavanaugh, yeah, I probably would have voted for him," McGrath said Wednesday.

"I didn't listen to all of the hearings. I don't think there was anything, and I'm not a lawyer or a senator on the Judiciary Committee, so I don't know the criteria," McGrath offered. "But I was very concerned about Judge Kavanaugh, what I felt like were the far-right stances that he had. However, there was nothing in his record that I think would disqualify him in any way. And the fact is when you have the president and the Senate, this is our system and so I don't think there was anything that would have disqualified him in my mind."

Although McGrath called Christine Blasey Ford's accusations of sexual misconduct by Kavanaugh in high school "credible," she reiterated that she did not view them as "disqualifying."

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"Well, I mean I think again, I think it's credible but given the amount of time that lapsed in between and from a judicial standpoint, I don't think it would really disqualify him," McGrath said.

Four hours after her remarks were published, McGrath tweeted a mea culpa that immediately drew scorn from both Democrats and Republicans.

"I was asked earlier today about Judge Brett Kavanaugh and I answered based upon his qualifications to be on the Supreme Court. But upon further reflection and further understanding of his record, I would have voted no," McGrath wrote.

She continued: "I know I disappointed many today with my initial answer on how I would have voted on Brett Kavanaugh. I will make mistakes and always own up to them. The priority is defeating Mitch McConnell."

Reaction on social media was unsparing.

"This, my friends, is what we call an unforced error," journalist Yashar Ali observed.

"Take your third position on this later, the night is young," said Jake Wilkins, the communications director for North Dakota Sen. Kevin Cramer.

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Read the headline of an article on the left-wing blog Jezebel: "Unfortunately, the Woman Trying to Unseat Mitch McConnell Also Kind of Sucks."

McGrath narrowly lost a House race to an incumbent Republican in Kentucky last year. During that race, McGrath slammed Kavanaugh and suggested she would not support his confirmation -- leading some prominent commentators on social media to charge that McGrath's flip-flop was actually multi-layered.