Heitkamp was never going to change parties, she IS the ND Democrat Party. If she had accepted a potential offer for a Cabinet seat, which she and anyone else with a brain knew was an attempt to replace her with a Republican, she would’ve become the most unpopular Democrat within the party in the nation. She wasn’t going to do it.
As for her voting record, it’s about in line with other Democrats. She scored a 15% Conservative rating from the ACU (American Conservative Union) in 2016. In 2017, she earned a goose egg, a 0%. 100% leftist. Her lifetime rating is 89% leftist. The likelihood that she would switch parties based on that record is about the same of you giving birth to an anvil in the next 60 seconds.
Now do Joe Mancin...