State lawmakers in Arizona are sparring over legislation that would give a Republican successor to Sen. John McCain a pass on having to stand for election in November even if the ailing six-term senator resigns or dies before the end of next month.

Leaders of the Republican-controlled state Senate say they plan a vote next week on the measure, which could have implications on control of the U.S. Senate and has intensified the spotlight on the health of McCain (R-Ariz.), who is battling brain cancer.

Democrats have cried foul and are vowing to block the bill, which they say reflects how worried Republicans are about defending GOP-held seats, even in a red state like Arizona. The state’s other U.S. Senate seat is also on the ballot in November, as Sen. Jeff Flake (R) is not seeking reelection.

Under current law, a McCain successor appointed by Gov. Doug Ducey (R) after May does not have to stand for election until 2020. The legislation in question expands that window to include anyone appointed between now and then, as well.

“They don’t want to have to go up against the voters,” state Sen. Steve Farley (D), the assistant minority leader, said of the Republican leadership, adding that everyone’s hope is that McCain recovers.

Senate President Steve Yarbrough (R) acknowledged that the legislation could have implications for a McCain successor but that was not its intent, saying Democrats have overreacted.

“Maybe they’re giving us more credit than we deserve,” Yarbrough said. “I think it’s turned into something that it’s not.”

With Republicans holding just a 51-to-49 seat majority in the U.S. Senate, many races across the country have taken on heightened significance as Democrats hope to parlay President Trump’s unpopularity into a takeover of the chamber.

McCain, 81, was diagnosed in July with glioblastoma, an aggressive form of brain cancer that took the lives of Sen. Edward M. Kennedy (D-Mass.) and Beau Biden, son of former vice president Joe Biden.

McCain was hospitalized last weekend in Arizona for surgery needed to counter an intestinal infection.

His office did not respond to a request for comment on the pending legislation in Arizona.

The legislation was originally introduced to clarify the procedure for replacing congressional members following a scramble that followed the December resignation of Rep. Trent Franks (R-Ariz.). Franks faced allegations that he had asked female staffers to act as a potential surrogate for him and his wife.

Under current law, as interpreted by the secretary of state, an appointed senator must appear on the ballot in an election year if the appointment is made by May 31. A provision added to the pending legislation would push that date back to March 31.

The issue came to the fore earlier this week, when the Senate amended the bill to make it an “emergency” measure, meaning it would take effect immediately and potentially affect a McCain successor appointed in coming weeks.

Under normal procedures, the bill would not take effect in time to affect this year’s election. The amendment was added to the bill “quietly” and passed on a voice vote after no debate, Farley said.

“I think there was hope from some of the proponents that no one would notice,” he said.

Now that Democrats are fully engaged, there is an effort underway to block the bill.

Under legislative rules in Arizona, emergency bills require a two-thirds vote to pass. Republicans hold 17 seats in the 30-member Senate, meaning they would need several Democratic votes.

The bill would also need to be approved by the House, where Republicans similarly have a majority but not a large enough one to pass the bill without some Democratic support.