David Schapira, a former Dem primary opponent/friend of Krysten Sinema, spills the tea:

[InstantGratification]

40. "highly lucrative career after the Senate"

I think that is her fall back position. By switching to Independent, she has taken the primary challenge that was surely coming to her completely off the table. She gets a free pass to the general election while her R and D opponents have to spend resources in the primary while she banks hers for the fight that matters.

She is daring Democrats to run a 3 way race against her and the Republican. If D's do it, she will peel off enough D voters to tank the race and hand it to the R. It's almost blackmail: Run against me and lose the seat to a Republican who will always vote against you or support me and get my vote sometimes, usually with strings attached to appease me. I think the phrase is making "the Devil's bargain."