COLUMBUS, Ohio (AP) — Three-term Democrat U.S. Senator Sherrod Brown The Ohio lawmaker faces perhaps the toughest re-election challenge of his career on Tuesday in the most expensive Senate race of the year as control of the chamber hangs in the balance.

Brown, 71, one of Ohio's best-known and longest-serving politicians, faces Republican Bernie Moreno, 57, a Born in Colombia Cleveland businessman who was endorsed by former President Donald Trump in a contest Expenses have increased 500 million dollars.

Trump appeared in commercials for Moreno in the final weeks of the contest, while former Democratic President Bill Clinton joined Brown for a campaign rally in Cleveland on Monday.

Brown has defeated notable Republicans in the past. In 2006, he entered the Senate by defeating moderate Republican incumbent Mike DeWine, another well-known name in state politics.

DeWine, who is now governor of Ohio, separated from Trump in the primary and supported a Moreno opponent, state Sen. Matt Dolan — even though he was behind Moreno when he won. In October, former Gov. Bob Taft, the Republican scion of one of Ohio's most famous political families, said he supported Brown.

However, Ohio has shifted sharply to the right since 2006. Trump won twice the state by a wide margin and deprives it of it long-standing pioneering status.

Brown's campaign has sought to appeal to Trump's Republicans by highlighting his work with presidents of both parties and wooing independents and Democrats with ads touting his fight for the middle class. In the final weeks of the campaign, he was particularly tough on Moreno on abortion, casting him as out of step with the 57% of Ohio voters who supported it enshrined in the law to access the procedure in the state constitution last year.

Moreno, who would be Ohio's first Latino senator if elected, called Brown “too liberal for Ohio” and questioned his positions on transgender rights and border policy. Pro-Moreno ads portray Brown as an extension of President Joe Biden and his running mate, Democratic presidential candidate Kamala Harris, particularly on immigration. This then exploded as an election issue in the state Trump wrongly claimed during his debate with Harris that immigrants in the city of Springfield, Ohio, were eating people's pets.

Brown remained slightly ahead in some polls before Election Day, but others showed Moreno – who has never held public office – successfully closing the gap in the final stretch. Trump's endorsement has not yet failed in Ohio, including as he supported first-time candidate JD Vance – now his vice president – for the Senate in 2022.

Because Moreno and his Republican allies consistently outperformed Democrats during the campaign, they wanted to weaken Brown's popularity among Ohio voters. He remains the only Democrat to hold nonjudicial statewide office in Ohio, where the GOP controls all three branches of government.