New Delhi, April 30 -- Janet Mills, the Democratic governor of Maine and a vocal critic of US President Donald Trump, has dropped her bid to challenge Republican Senator Susan Collins, dramatically reshaping one of the most closely watched Senate contests ahead of November's midterm elections.

Mills announced her withdrawal on Thursday, citing a lack of campaign funding despite her popularity and political experience.

"While I have the drive and passion, commitment and experience, and above all else - the fight - to continue on, I very simply do not have the one thing that political campaigns require: the financial resources," Mills, 77, said in a statement.

Her decision clears the field for Democrat Graham Platner, a progressive candi...