While Michigan memorably went against the Democrats in the 2016 presidential election, incumbent Democrat Debbie Stabenow has a huge lead of up to 20 point over her Republican rival John James in recent polls. So I’d recommend that you take Betfair’s 1.15 (86.9%) on the Democrats winning.
Texas should be an easy contest to call. It is the quintessential red state, voting for the GOP in every presidential contest since 1976. Changing demographics have given the Democrats hope that this could change, but incumbent senator Ted Cruz remains popular and the polls indicate that he remains on course for a solid victory. I’d therefore take Betfair’s 1.15 (86.9%) on the GOP winning.
Mississippi has also consistently voted Republican for the last four decades. There are two Senate elections there: the regular election involving Roger Wicker, plus a special election to replace the retiring Thad Cochran. Betfair is offering 1.11 (90.9%) on the GOP winning the regular election. Normally, I’d be reluctant to recommend such short odds, but given that Wicker has a 17-point lead in the one poll conducted so far, I’ll advise you to take it.