Arizona lawmakers are debating legislation that would keep John McCain’s Senate successor off the ballot in November’s midterm elections, should the seat become open before the end of next month.

The bill, which could come up for a vote this week, would change the state’s process for replacing members of Congress who resign or die in office. Though Democrats are expected to block the measure, the effort has renewed speculation about McCain’s health.

McCain, a six-term Arizona senator and 2008 Republican presidential nominee, was diagnosed last summer with glioblastoma, an aggressive form of brain cancer. The 81-year-old has been with his family, absent from Washington, since December.

State Democrats accused Republicans of playing politics with the bill by trying to eliminate the possibility of two open US Senate seats in a year when the state could determine control of Congress. Nationally, the historic unpopularity of Donald Trump is fueling talk of sweeping Democratic gains.

Arizona Republicans are already defending the seat that will be vacated by retiring senator Jeff Flake. The battle to replace him is expected to be one of the fiercest – and most expensive – midterm races.

“Where there’s smoke there’s fire,” Democratic state senator Steve Farley, the assistant minority leader, told the Guardian. “The effect of this bill would be to allow a Republican to serve in that [US] Senate seat without standing for election in a year when things aren’t looking like they’re going well for Republicans.”

Republicans say that is not the their intent. Steve Yarbrough, the Arizona senate president, did not immediately respond to a request for comment from the Guardian. But he recently told the Hill: “I think everybody was just trying to make this process fair. I think it’s unfortunately probably much ado about little. It’s not like this is going to create some advantage.”

Debate on the issue erupted this week, when Republicans moved to amend the legislation one day after McCain’s office announced that he had undergone surgery related to an intestinal infection.



In the event McCain’s seat becomes open, Governor Doug Ducey, a Republican also up for re-election this year, will make an appointment. The seat would appear on the next general election ballot.



The Arizona secretary of state’s office has said that if the vacancy occurs before 31 May, voters will elect a new senator in this year’s general election. If the seat opens after that date, the appointee will serve through 2020.

By introducing an “emergency clause” to the bill concerning succession to vacated congressional seats, state senate Republicans proposed changing that deadline to 150 days prior to a regular primary election, or 31 March of this year. That would ensure that McCain’s seat did not appear on the ballot in November.

Without the emergency clause, the legislation would not take effect in time to impact the 2018 election.

The legislation was originally a bipartisan effort to clarify existing law on special elections, prompted by the resignation of Trent Franks, a US representative who stepped down in December amid allegations of sexual misconduct.

Farley said the emergency clause, which requires a two-thirds vote, was added “quietly” and “without debate”. Republicans will need support from several Democrats to pass the bill as amended. Farley said that will not happen.

And even if the bill were to pass the Arizona senate next week, it would still need to be approved by the state House. Whether Governor Ducey would sign such legislation also remains uncertain.