Construction trucks bound for a data center site near Hillsboro, Texas, clattered through the town square, drowning out conversation and tossing dust onto the outdoor tables of Kelley and Michael Ivy’s burger restaurant. “People can’t even sit outside,” Ms. Ivy said. Both longtime Republican voters, the couple opposed the nearby construction because of concerns about its impact on the landscape and local water systems. They blamed Republican state leaders, like Gov. Greg Abbott, and wanted a change. Would they vote for a Democrat in the fall? Neither said they would.

The rush of data center construction has fueled a potent bipartisan backlash across the country this year, creating unusual political alliances ahead of the November midterms. Democrats hope the anger will weaken Republicans among some of their most reliable rural voters. Republicans are betting that although those voters may dislike data centers, they are not ready to abandon the party over them. The stakes are particularly high in Texas, home to more data centers than any other state except Virginia.

Late last year, Mr. Abbott crowned Texas the “epicenter of A.I. development.” Up to half of the nation’s new data center capacity predicted from 2027 through 2030 is expected to be built in the state, according to Jefferies. Then last month, Mr. Abbott abruptly called for a pause on connecting hundreds of large data centers to the state’s power grid until the projects underwent a full audit of their local impacts. That process is likely to stretch beyond the election in November.

Public backlash has also extended to energy projects in Texas, imperiling plans to build high-voltage transmission lines. Without new lines, the Permian Basin is at risk of rolling blackouts, according to the Electric Reliability Council of Texas. Mr. Abbott’s decision was a sign of how fraught the politics have become. Many Republican voters have turned against the projects, some even joining with Democrats to fight them. Elena Voytko, a conservative Christian opponent in Temple, Texas, said finding common cause with Democrats had not changed how she planned to vote. Democrats hope the anger will dampen Republican turnout, while Republicans bet the issue will not motivate enough average voters.