Former Vice President Joe Biden, with the backing of John Kerry, the state’s longtime senator and the 2004 Democratic presidential candidate, won a surprise victory in the Massachusetts presidential primary on Super Tuesday, besting home-state candidate Elizabeth Warren and frontrunner Bernie Sanders, who is from neighboring Vermont.

It was a crucial win for Biden, not least because it denied a victory to Warren, who will likely face heavy pressure to drop out after losing her home state.

With 91 delegates at stake, Massachusetts is the fifth-biggest contest of Super Tuesday, after California, Texas, North Carolina, and Virginia.

The state was not a major focus of campaigning or ad buys by the candidates, though Mike Bloomberg, with his essentially unlimited financial resources, still spent millions on TV ads and tried to build out a field operation, apparently to little avail.

Polling was scarce before the last week of the primary, and the final three polls all showed a close race. The public radio station WBUR found Sanders ahead with 25 percent, followed by Warren at 17 and Pete Buttigieg (who dropped out over the weekend) and Bloomberg at 14 and 13, respectively. The polling firm Swayable had Sanders in first with 27 percent, followed by Bloomberg with 17.9 percent, Biden with 17.3 percent, and Warren in fourth with 14.6 percent. Data for Progress’s poll had Warren in first with 28 percent, then Sanders and Biden tied at 26, and Bloomberg at 15.

In other words, while Biden’s victory was a surprise, it was well within the realm of possibility based on the polling data we had going in.

Last Super Tuesday in 2016, Massachusetts was one of the most heated battlegrounds between Hillary Clinton and Bernie Sanders, with the former very narrowly edging out the latter, 49.9 percent to 48.5 percent, a difference of barely 17,000 votes. Clinton had decisively defeated Barack Obama in the caucus eight years prior, despite Obama’s support from Sens. Ted Kennedy and John Kerry and then-Gov. Deval Patrick. Warren had the support of most of the Massachusetts congressional delegation and the Boston Globe this time around, while Kerry and Rep. Stephen Lynch endorsed Biden.

Patrick himself made a late, abortive attempt to run for the Democratic nomination before suspending his campaign following a dismal ninth-place finish in the New Hampshire primary.