The Lib Dems do seem to have come up with some rather stupid statements recently.
The polling claim in Bath and North East Somerset is in line with what all political parties do, i.e. create a narrative designed to achieve whatever they want to achieve regardless of whether that narrative has any basis in reality. This technique has developed over time so now it is ubiquitous to the extent of being ludicrous. The more all parties use this technique the more it becomes obvious what they are doing even to the least questioning voter and the more credibility they lose. I would judge that the majority of MPs in Parliament today, in all parties and on both sides of the Brexit debate, are asymptotically approaching zero credibility, at least among thinking voters if not tribal ones.
I also think that the claim that ITV's decision to host a debate only between Johnson and Corbyn is sexist, i.e. Swinson has been excluded because she is a woman, is complete twaddle. ITV claim that they have done so because realistically only Johnson or Corbyn can become Prime Minister. While probably factually true that claim is also twaddle. ITV want to host a leaders' debate because they think it will be good for ratings and hence advertising. They couldn't care less who is in the debate as long as they get it. Neither Johnson nor Corbyn want Swinson in the debate because they can remember what happened in 2010. Whatever you think of him, Nick Clegg's performance in those debates cost both Cameron and Brown votes that resulted in a hung Parliament and a coalition government. The Lib Dems pose a real threat to both Labour and Conservative votes for any remain leaning voter so both Johnson and Corbyn want her to get as little air time as possible. I doubt if they would have agreed to the debate if she was included for that reason and nothing to do with her gender.
I think it is highly probable, because of the Brexit issue, that the Lib Dems will get an increased vote and probably an increased number of seats, despite the first-past-the-post voting system, but the probability of them winning an outright majority is vanishingly small. I don't know what Swinson's advisers are telling her but every time she says that she is standing to be PM she appears increasingly delusional. Personally I would be less likely to vote for someone who appears delusional.
PS Please note that I am neither anti nor pro any political party nor do I have any political affiliation Whenever I take the Political Compass
test, however I do find myself in a position on the chart that is closer to the Lib Dems than either Labour or Conservative so I presume I must have more in common with them. Given that closeness in ideas, if I am critical of their actions how are they going to attract voters who are further away behaving in this way?