An unpopular war in the Middle East and voters’ discontent with the cost of living have put Democrats within striking distance of repeating a historic victory notched exactly two decades ago, when the party pulled off a stunning Senate upset to win control of Congress.

A Democratic-controlled Senate could block President Donald Trump’s nominees, including to the Supreme Court, investigate the president and his allies, hold leverage over the federal budget and set the rules for a potential third Trump impeachment trial.

Democrats have long been favored to win the House, where they need to pick up just a handful of seats across the country. The path to Senate victory is narrower and more arduous, requiring the party to pick up at least four seats, including at least three in states Trump won.

It’s a stretch, especially with Republicans holding a fundraising advantage, including a plan this week by the GOP-aligned Senate Leadership Fund to allocate $342 million to the key battlegrounds. But Democrats have history and momentum on their side. In 2006, another Republican president with fading popularity in the middle of his second term — George W. Bush — lost both the House and, more surprisingly, the Senate amid waning support for the war in Iraq.