"Chris MurphyChristopher (Chris) Scott MurphyLawmakers feel pressure on guns Trump to take steps to ban bump stocks Kasich’s campaign website tones down gun language after Florida shooting MORE is not happy that his lack of a work ethic has been exposed, but that’s the least of his worries," says an email from campaign manager Corry Bliss that goes along with the ad.

"Summarize" comes just a day after the release of a poll that showed McMahon leading Murphy by three percentage points. But a new poll flips that lead, with Murphy ahead of McMahon by four percentage points.

According to the poll from left-leaning Public Policy Polling, Murphy has 48 percent support to McMahon's 44 percent support. McMahon's favorability numbers are split pretty evenly in the poll, with slightly more -- 47 percent -- of voters rating her unfavorably than the 45 percent who have a favorable opinion of her, and only eight percent of voters are unsure about the candidate.

Murphy faces a similar gap in his favorability numbers, with 41 percent of voters viewing him unfavorably and 39 percent viewing him favorably -- but a full 20 percent of voters are still unsure about him.

The new poll also indicates Connecticut voters mostly have their minds made up, with only 8 percent of respondents saying they're still undecided in the race.

It was conducted among 881 voters from Aug. 22-23.