Mark Halperin

She's the only New England senator Republican.

She's the rare senator who represents a state that her party's presidential candidate didn't win.

But she's a survivor.

She will not be easy to beat.

We'll talk more about that.

North Carolina, an open race, a Republican-held seat.

Democrats have a very strong candidate there.

That may be their best pickup opportunity.

But it's not a slam dunk.

We'll talk about that.

then and then finally ohio republicans have an incumbent but he was an appointed incumbent he didn't win the seat democrats have a strong candidate okay none of those are shoe-ins for the democrats truly but those are their best bet so if you take those six again three republican health seats three democratic health seats

I'm telling you, mathematically, just as a matter of the politics of it, Democrats have to go six for six.

They have to win every one of those.

If Republicans win a single one of those six, they're almost certain to keep the majority.

Not 100% certain, but almost certain.

So again, just think about the rules of the game.

One side needs to win six in a row, and the other side just needs to pick off one.

And even if Democrats go six for six in those races, they still need to win one more, most likely from Texas, Iowa, or Alaska.

None of those are sure things for the Republicans, for the Democrats at all.

First of all, they're all red states.