Arnold Schwarzenegger accuses US states of trying to 'out

Arnold Schwarzenegger has accused US politicians of attempting to "out-cheat" one another as next year's mid-term elections close in.

Speaking to CNN on Sunday, the 78-year-old movie star railed against a gerrymandering arms race currently playing out between states.

"This is spreading like wildfire all over the country," he said.

Here is a quick breakdown of what is going on.

First, what is gerrymandering?

It is a tactic political parties use to gain an advantage at elections.

Federal electorates in the US (known as congressional districts) are decided by each individual state, and not necessarily by an independent commission.

Because of that, politicians in many states can redraw federal electorates — a practice called "redistricting" — to include more voters in favour of their pa