Texas divided in 5

Suppose that some time in 1850-s, Texas acts on the promise of the Congress and is divided in 5 states.

The representation of Texas in Senate goes from 2 to 10. The number of Representative seats goes up from 2 to 5 (each state has a minimum of 5). The representation in Electoral College goes from 4 to 15.

Will it make a change in Presidential Election of 1860?

"Each state has a minimum of five [representatives]"?
No, each state has a minimum of 1 representative, 2 senators, 3 electoral votes.
Anyhoo, most, probably all, of these 5 states will only have 1 representative.

The effect on any election will likely not be large in the popular election, but will affect the Electoral College. Instead of his 72, Breckinridge will earn 83 electoral votes. Lincoln still wins with 180 votes, however, so no change there.
More than anything, I think the addition of 4 new slave states will have more effect overall, if not for long. The real effects of 5 Texas' will be seen more prominently later, I imagine.

I very much doubt it would be five slave states. Probably two would not be slave states. A lot would depend on how it'd be divided, but slavery in TX was concentrated in the areas between today's Dallas and Houston. There were virtually none in the Rio Grande valley.

And that's not taking into account the outside pressures from abolitionists and proslavery people. More than likely they'd try to arrange to keep the balance between free and slave states. My guess is two free states and three slave. The free states would likely be one in the Rio Grande valley and the other is west Texas, at that time sparsely populated outside of the El Paso area and Indian tribes.

Well, to be fair, if we're taking into account how they decide to divide it up, it's not likely to be divided up at all if they're not slave states. That said, it's actually pretty unlikely that it'll be divided into 5 states, 2 or 3 is more likely.

See a thread I had over a similar topic, here.

1850s?

I'd say the Northern states now have enough clout to keep all of the states from becoming Slave states. But not enough power to make them all free (Obviously).

I say three states: One Free State, and Two Slave states.