Previous CHP figureheads have failed to inspire enthusiasm, even among the party’s loyal followers, but Ince, a powerful orator credited with a record of challenging the ruling Justice and Development Party (AKP) in parliament, has changed all that.
“Muharrem Ince is one of us," enthuses Atila Sertel, a CHP MP who is defending his seat in Izmir in the general election, which also takes place on Sunday. "He is the son of a farmer and he lived in a village. That’s why people think he is close to us.”
Earlier in the campaign, Meral Aksener was tipped to be Erdogan’s most serious challenger.
She is a secular right-winger who split from the Nationalist Action Party (MHP) when it supported Erdogan’s constitutional reform in last year’s referendum.
She set up her own Iyi (Good) Party and hoped to appeal to conservative voters who might desert Erogan because of the economic crisis that has hit the country.
But Ince has proved to have the common touch, making an effort to appeal to poorer Turks, many of whom are devout Muslims alienated by the urban secular elite.
He has also made an effort to win over the country’s Kurdish minority, whose demands for language rights and more self-rule have been dismissed by the CHP in the past.
Ince was on home territory on Thursday when he addressed a rally in Izmir, a secular stronghold on the Aegean coast.
The CHP has 14 MPs there compared to the AKP’s eight.
Its share might even go up on Sunday, when theere is also a legislative election in which the opposition hopes to deprive the AKP of its majority in parliament.
On Thursday morning, ahead of the rally, many Izmir residents were enthusiastic about Ince.
Some of them, like housewife Arzu Demir, have voted for the MHP in the past.
She described Erdogan as “a thief”.
“Honesty is important,” she said. “Also there are no green spaces. If you can see them, one year later they’re not there.”
Erdogan has fuelled a building boom, which has boosted growth to a healthy 7.5 percent but also, his critics allege, enriched his cronies.
Integrity was also on labourer Muslum Yildirim’s mind.
Ince because is honest and wants to the unite the nation, he said, but he feared the CHP candidate might be literally robbed of victory. “The most important thing is that the votes are not stolen. I’m afraid he won’t win because votes are stolen during the election.”
Yildirim, who has two children, hopes the next president will improve education and represent all Turks, not just his party’s voters.
“I’m thinking about the economy and that’s how I will decide,” said accountant Tarik Kaloy.
Until recently, the AKP has had a good economic record but now the lira has plunged against the dollar, inflation is 12 percent and unemployment is about 10 percent.
“I’m also worried about terrorism,” Kaloy added, in reference to the war with the separatist Kurdistan Workers Party (PKK) in the south-east of the country.
Another issue on voters’ minds is the several million refugees from the Syrian conflict who have come to Turkey.
Erdogan has reached a deal with the European Union to keep them here, in exchange for three billion euros to help with the costs.
But some Turks complain they have been given homes and money while local people do without.
Ince has said he will send some of them back; Aksener says she wants to throw out four million Syrians.
Not that the CHP has it all its own way in Izmir.
Leyla Arslan Giray, a Kurdish shopworker, is voting for the left-wing, Kurdish-based People’s Democratic Party (HDP), one of whose candidates in the area is an Afro-Turk.
And there are some AKP voters.
“I’m voting for Erdogan not only because he has built bridges and roads but because has done a lot of good for the country,” says electrician Bayron Altunkonat. “Before, the other parties did nothing for the country but Mr Erdogan has done a lot for the country.”
Can Ince win voters from the AKP?
CHP MP Sertel thinks so.
“Poor people love him," he says. "He said he is not going to live in the presidential palace. He said he is going to turn into a scientific centre. There’s a summer residence with 300 rooms and he is going to change it so that disabled citizens can use it. That’s why he can win votes from the AKP.”
Some Erdogan supporters admire the taste for glitz that has led to the construction of a vast new presidential palace, considering it worthy of a strong leader and pointing out that the president has made his way up from humble beginnings.
But opinion polls show a fall in support for the AKP.
The polls have proved unreliable in the past.
But Muharrem Ince and his opposition alliance insist there is disillusion with Erdogan and believe that means they can win this time.