A 4-term Senator polling in the lower 40's is insanely weak. Undecideds usually break more for the challenger, so Collins is in serious trouble. Have the ads even started yet pointing out that she voted to acquit a clearly criminal president? That she put her political party before her country? Yeh, I don't see her pulling this out. There's waaaaay too much of Trump's insane appointments/policies to tie her to, and HUUUUURRRR DUUUURRRR MY OPPONENTS A LIBRUL HHUURRR DUUURRR BERNIE SOCIALSIM DUURRRRR isn't gonna save her. With the Assange news today she might be forced to vote to acquit Trump again just before the election, and that will kill any remaining chance.
Especially when Bernie would likely win Maine against Trump.