Admittedly, bipartisanship is a tricky concept on which to base a political campaign, and not only during primary season. After all, you’re trying to beat the other party in the next election. And in a midterm election, the logic of bipartisanship could compel voters in the president’s party to give control of Congress to the opposition, and provide a check on the presidency.

But Democrats can argue that thanks to lawmakers like Kyrsten Sinema, Democrats are building bipartisan coalitions with reasonable Republicans to make headway on tough problems. That cooperative spirit will continue only if the Democratic Party remains in control of Congress. Otherwise, Donald Trump – putting his political needs ahead of the public’s needs – will pressure congressional Republicans to stop cooperating with Biden, and this newfound spirit of bipartisanship will be extinguished.

Progressive activists likely won’t be impressed by Sinema’s growing record of bipartisan deal-making, as her deals don’t come close to the sweeping agenda they hoped could pass in this Congress. But many of her critics presumed that Republicans were incapable of playing a constructive role of any sort during a Democratic presidency. They should at least concede that Sinema has been more successful than they anticipated, and recognize she is a valuable asset who can help keep Democrats in power.