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Democrats’ only real opportunity to set up a roadblock in front of President Donald Trump during his remaining years in office comes with next year’s midterm elections. They’d need to pick up just a few seats to take control of the House.

But Republicans want to game the system by pursuing a rare effort to redraw congressional lines in multiple key states and squeeze more seats out of delegations already designed to favor them.

“Very simple redrawing. We pick up five seats,” Trump said recently at the White House, referring to an ongoing effort by Texas Republicans. But the effort extends to other states as well.

It also may not be so simple. The strategy, which is playing in various ways across the country, could backfire if Republicans turn safe seats into competitive ones in the long-shot event that these redrawing efforts succeed and are blessed by courts.