WASHINGTON — Acutely partisan and all but dysfunctional, Congress has completed its most elementary task after an intense weekslong struggle, finalizing a deal to fund the government just days ahead of a shutdown deadline.

The legislation extends existing spending levels a mere 10 weeks, past Election Day, while finally addressing the Zika crisis with $1.1 billion and providing long-sought help for the residents of Flint, Mich., as well as flood victims in Louisiana. After a last-minute burst of deal-making, the legislation passed the Senate on a 72-26 vote Wednesday and was backed by the House 342-85 in a late-night vote Wednesday.

It was a conclusion in sight and within reach since lawmakers returned from their summer recess just after Labor Day. But with the Capitol awash in election-year politics and shadowed by the contentious presidential race and engulfed in a fierce battle for control of the Senate, the simplest task became a nearly impossible heavy lift impeded by needless delays and bitter finger-pointing.

Republicans, defending a fragile Senate majority and eager to get a handful of vulnerable incumbents back home to campaign for re-election, accused Minority Leader Harry Reid of holding up a deal to keep GOP lawmakers off the campaign trail.

“The Democrats are determined to keep us here as long as they can,” groused one at-risk Republican senator, Pat Toomey of Pennsylvania.

Democrats denied it but lobbed their own allegations, all but accusing Republicans of racism for holding up money for people affected by lead-tainted water in predominantly black Flint, the final sticking point in the talks.

“All they’d have to do is put Flint in and we’d be out of here in a minute. We want to get out of here. They’re the ones holding it up,” complained Democratic Sen. Chuck Schumer of New York.

Compromise on a $170 million Flint aid package ultimately gave Democrats a partial victory while the GOP-dominated Louisiana delegation won a down-payment on President Barack Obama’s $2.6 billion request for their state. The Zika deal was the resolution of a long and vexing dispute on that issue after Obama made his initial request for federal money in February.