Whether you think this idea makes economic sense or not (similar projects in Sydney and Brisbane have been financially problematic), it is clever politics.
Rail links to airports seem to be about state pride as much as anything. Every self-respecting big city reckons they should have one.
The idea is wildly popular and Denis Napthine is clearly keen to market himself as an infrastructure premier.
Addressing the Liberal Party state council on Sunday, Dr Napthine had a compelling story to tell: Victoria's population has been booming. In the past 12 months it grew by 110,000, with more than 2100 people flooding in each week. Passenger numbers at Melbourne Airport are expected to double to about 60 million a year within 20 years. While Public Transport Victoria has warned the benefits of a direct airport link are at present outweighed by the ''high costs'', at some point it will become vital, particularly with CityLink already close to capacity.
But there are also risks. The idea has been on the agenda now for decades (40 years according to the Premier). Voters might rightly be cynical, particularly with plans for rail lines to Doncaster, Rowville and Avalon still no closer to being delivered.
The budget may well ''outline'' the government's ''commitment'' to the link but whether it will fund it over the four-year budget period is a different question.
There are also questions about how the project will mesh with the ''realigned'' Metro Rail project, which is undoubtedly a far more urgent need for Melbourne's rail network.
Finally, whether Dr Napthine's major projects agenda is now overcrowded is up for debate. As Treasurer Michael O'Brien has pointed out, too much ''overlap'' between projects can force up costs by creating labour shortages.
Dr Napthine, on the other hand, reckons the government can ''walk and chew gum at the same time'' by building both the airport rail link and the Metro project simultaneously.