Sen. John McCain’s hospitalization last week revved up speculation about who might succeed the six-term senator if cancer forces him to leave the Senate.

On this weekend’s “Sunday Square Off,” our panel looks ahead to Arizona’s potential Senate matchups in 2018 - a fall election for retiring Sen. Jeff Flake’s seat, as well as a race for McCain’s seat.

We look at the potential candidates - with some surprising names - and why Arizona voters could decide control of the U-S Senate.

Also on this weekend’s look ahead to 2018, panelists Lisa Fernandez, political consultant and vice president at Resolute Consulting; Christine Jones, a former Republican candidate for governor and former top executive at GoDaddy; and political analyst Chris Herstam discuss:

-Governor Doug Ducey is running for a second term. Does he have anything to worry about?

-Arizona education voters are fired up like never before. Will they make a difference?

-Immigration has been a top issue in Arizona elections for the last decade. How will the deadline for protecting Dreamers figure into the 2018 campaigns? “Sunday Square Off” airs at 8 a.m. Sundays on 12 News, after NBC’s “Meet the Press.”