A group of Republicans is rallying together in an attempt to stop Donald Trump from gaining the party’s nomination at their convention next week. The convention is where the party will officially select its presidential candidate. But just because Trump is the only hopeful left standing after the state primaries does not mean Republicans have stopped their fight over the nomination.

How will they do it?

Throughout the primaries, presidential hopefuls have earned delegates based on how citizens voted.

Donald Trump amassed 1,542 delegates, over 900 more than Ted Cruz, the candidate with the second highest delegate count.

Some of these delegates are “bound” delegates, meaning they must vote for a certain candidate.

Unbound delegates may vote for any candidate.

But some bound delegates are refusing to vote for Trump despite their status as a bound delegate.

Arizona delegate Lori Hack announced Sunday on her Facebook page that she would not be voting for Trump, despite the fact that rules say all of her state’s delegates are bound to him.

“Simply put, he doesn’t represent our party, and he can’t win in November,” Hack wrote.

Some bound delegates could be subject to fines or, in some cases, jail time for not voting according to their bound status.

Carroll Correll Jr., a delegate from Virginia, filed a lawsuit arguing that he should not have to vote for Trump.

Last month, ABC News reported that about 1,000 delegates joined in a conference call to talk about efforts to change the Republican National Convention.

Participants in the call had their focus on unbinding all delegates, making it acceptable for them to vote for any candidate they choose.

This requires work in the Convention Committee on Rules and Order of Business, or Rules Committee, which meets the week before the convention.

This committee of 112 members, a male and a female from all U.S. states and territories as well as Washington D.C., shapes the rules that will be used at the Republican National Convention and governs the party for the next four years.

On July 18, when the convention officially begins, convention delegates will be presented with what the Rules Committee has approved.

The rules must then receive a majority vote from  convention delegates.

In order to successfully affect the Rules Committee, proponents of the change must convince a quarter of the committee members that granting delegates “unbound” status is a good idea. Support from those 28 will allow the changed rule to be presented to convention delegates for approval.

Why change the rules?

The bound delegates who like the idea of a rule change voice different reasons behind it. For one, some bound delegates are now expected to cast votes for individuals that are no longer in the race.

“My guy is off the stage,” said Brita Horn, bound delegate for Ted Cruz, according to ABC News. “Based on old rules, I have no vote. It won’t count. Why not support being unbound and vote freely?”

Some delegates no longer want to be bound because they feel uncomfortable with Trump and do not want to vote for him.

According to The Wall Street Journal, 890 delegates are loyal to Trump, 680 are not, and 900 are considered up in the air or “in play.”

“If we are a party of liberty, what are we afraid of?” said Gina Blanchard-Reed, a delegate from Washington state, in an email to others who are on the Rules Committee with her. “What are we unwilling to do? Does it mean that Donald Trump would be denied the nomination? Possibly. Possibly not. He would come out of the Convention stronger if he won the nomination as a result of a free will vote.”

Steve Lonegan, one of the leaders of the movement seeking to change the rules, claims this is not about trying to replace Trump with a specific candidate.

“This is about allowing the delegates to do the job they’re elected to do,” Lonegan said.

Right now, there is no word on who would take Trump’s place.

The Anti-Trump movement is not proceeding unopposed.   

There are efforts from within Trump’s campaign and elsewhere that do not want the rules to change.

“Why do you have primaries?” said Peter Feaman, committee member of the Republican National Convention, reported PBS. “Why caucuses? What’s the purpose? Only so when you get to convention that if a minority of people don’t like the outcome, they can change it? No. No.”

Republican Speaker of the House Paul Ryan has officially endorsed Donald Trump, but in June he told NBC News he does not feel he should be a leader in division in his party.

“The last thing I would do is tell anybody to do something that’s contrary to their conscience,” Ryan said. He said Republican House members do not have to support Trump. “Of course I wouldn’t do that. This is a very strange situation. This is a very unique nominee.”