They know that this is the only way they will be allowed to win an election and winning is all that matters to them.
What will happen when they do win will be a continuation of the way the country is governed under the Conservatives.
Starmer wants more economic growth, in other words trickle down economics, which just means people with a lot of money get more, nothing actually dribbles downward, nothing is redistributed.
West Streeting wants more private firms involved in the NHS, all that does is give more money to private firms, it doesn't help the NHS.
Rachel Reeves wants to reintroduce PFIs which were a false economy the first time round.
But those policies mean that they stand the best chance of not annoying the media, and winning.