Just as Barry O'Farrell knew he risked being undermined by the right wing of his party if he stood as opposition leader after the resignation of Liberal Party leader John Brogden in 2005, Berejiklian stepped aside for the sake of party unity.

She formed a "unity ticket" with Treasurer Mike Baird, making way for him to be elected as premier unopposed.

While Mr Baird is said to be philosophically aligned with Berejiklian's faction, known as the moderates, he is also supported by the right wing of the party. The right wing views Baird as a successful Treasurer, having maintained the state's triple A credit rating. He is conservative in his economics, has a strong Christian faith, but is also progressive in social views on issues such as the treatment of asylum seekers.

The right wing of the Liberal Party is split into three sub-factions. The soft right is understood to include Wollondilly MP Jai Rowell and upper house MP Matthew Mason-Cox. The centre right is said to include Baulkham Hills MP David Elliott, Hawkesbury MP Ray Williams, Family and Community Services Minister Pru Goward and Charlestown MP Andrew Cornwell. The so-called hard right, or "religious right", is understood to include Energy and Resources Minister Anthony Roberts, Castle Hill MP Dominic Perrottet, upper house MP David Clarke, Attorney General Greg Smith, upper house MP Marie Ficarra and former Energy and Resources Minister Chris Hartcher.

The dominant left-wing faction, the moderates, is understood to include upper house MP Don Harwin, Transport Minister Gladys Berejiklian, Hornsby MP Matt Kean and Londonderry MP Bart Bassett. Mr O'Farrell was independent, but loosely associated with the moderates, which gave him its strong support.

Members of the party's conservative right and centre right said they strongly supported Mike Baird as Premier.

One member of a right-wing faction said the three sub-factions backed Baird over Berejiklian.

"The right would have unified against her as leader," the MP said.

"She had been a factional heavyweight.

"Gladys wisely read that and withdrew. A number of right wingers thought that she showed loyalty to the party by doing that and said they would not stand in the way of her as deputy."

It is understood that the right wing would have supported Finance Minister Andrew Constance as leader if Baird didn't stand.

As the son of former NSW minister and Federal MP Bruce Baird, Mike Baird is viewed by some as Liberal Party establishment.

However, the factions are not clearly aligned in their philosophical views. For example, Ms Berejiklian is said to be in favour of privatising the state's remaining electricity assets, while right winger Chris Hartcher is understood to have been opposed to the privatisation, and is a republican.

"There are people who call themselves conservatives who are in favour of gay marriage and gay adoption," one MP said. "The factions are not more than preselection co-operatives."

A member of the moderates faction said former premier O'Farrell was successful in bringing the entire party behind him and creating an accord between the factions.

In 2007 when former Opposition leader Peter Debnam lost the state election there was broad agreement the party had been hijacked by the so-called hard-right and had become unelectable.

"Barry O'Farrell has united the party with the exception of a small group on the extreme right," one right-wing MP said.

When the right's Anthony Roberts bowed out of nominating for the position of deputy leader on Thursday, he said his decision "underscores the strength and unity of the NSW Liberals".

"I believe Mike Baird and Gladys Berejiklian will make a terrific leadership team for the NSW Liberal Party and I will be strongly supporting them," he said.