Can the opposition stop Erdogan's re-election as president?

The winner of Turkey's presidential elections will take office with more competencies than any Turkish president who has so far had, including the right to rule by decree and disperse parliament.

In hopes of preventing the re-election of Recep Tayip Erdogan, various opposition parties have joined the alliance for both parliamentary and presidential elections held today.

The National Alliance supports the secular candidate for president, Muharrem Incre, nominated by the Republican People's Party.
The alliance includes secular social Democrats, centre-right conservatives, liberal nationalist conservatives and conservative Islamists.
Candidates for parliament from the National Alliance pledge that if they secure most of the legislature, they will abolish the constitutional changes that were adopted in a contractary referendum in 2017. These changes are expected to take effect after the elections and transform Turkey's parliamentary system into the presidential system.
In addition to expanding presidential competencies, these changes will also remove the prime minister's post and abolish many checks and balances that are designed to assist parliament in the face of misuse of presidential competencies.
Erdogan's Justice and Development Party and its junior coalition partner, the Nationalist Movement Party, from the far right, have drafted constitutional changes and transformed them into law, with the goal of strengthening Erdogan's rule, a rule that many independent experts say is moving towards authoritarianism.
A Stair of Hope for Opposition Presidential Candidate

Erdogan's popularity appears to have faltered in recent months due to the worsening economy, his staunch opposition against Kurds throughout the region, and concerns about the continued persecution of political rivals since the failed coup effort in Turkey in July 2016.
Erdogan is thought to have strong chances of being re-elected even for a five-year term. But opinion polls show it will be difficult to win in the first circle and that he will probably go to the runoff against Inces on July 8th.
Gonul Toll, director of Turkish studies at the Middle East Institute, headquartered in Washington, tells Radio Free Europe that today's “elections could be the last chance for Turkey to avoid falling into authoritarianism, with Erdogan”.
Toll says Ince has the chance to defeat Erdogan in the second round of voting, if they are realised without irregularities.
But to do that, Tol says that Ince must achieve Kurdish support in Turkey and “convince religious conservatives that the religious freedoms they had under Erdogan's rule will remain in force”.
Nick Danforth, analyst at the Centre for Politics in Washington, tells Radio Free Europe that “if the votes are counted fairly, the opposition has a good chance of stopping Erdogan in the first round”.
“In the first circle, if the opposition joins all behind Inces and if the votes are rightly counted, Ince has the chance to defeat Erdogan”, Danforth says.
According to analyst Toll, even if there is no fraud in elections, the “election campaign has not been free and fair”.
She says Erdogan's crackdown, after the failed stamp, under a state of emergency, has oppressed opposition media throughout the country.
“If Erdogan wins the presidency, but his ruling party loses the parliamentary majority, I think parliament can still play a role in terms of the balance of Erdogan”, Toll says.
However, it will be extremely difficult to have a functional democratic system and restore Turkish democracy, even with a parliament controlled by the opposition. The ideal situation for Turkish democracy would be if the opposition wins both the presidency and parliament”, Tola concludes.