The former Democratic governor hails from a deeply red state that overwhelmingly backed Trump over former Secretary of State Hillary Clinton. Republicans have pointed to the fact that Kentucky's number of coal jobs has dwindled over the years, while Democrats have pointed to the creation of Kynect -- the health care exchange established as a result of Obamacare -- as improving health insurance coverage in the state.
Beshear's Republican successor, Gov. Matt Bevin, ended new sign-ups to Kynect.
Trends like these have converged to make Kentucky something of a barometer for Trump's agenda, and Beshear stands in a potentially unique position to respond to what the new White House scopes out for the country.
That in mind, here are a few things about the man himself.
How did he get here?
After years in Kentucky politics, Beshear became governor in December 2007 as Democrats made national gains in 2006 and 2008. After the Affordable Care and Patient Protection Act, now known as Obamacare, became law in March 2010, politicians and courts wrangled with the act. Quickly, governors around the country were left with a choice: embrace the law by expanding Medicaid and implementing healthcare exchanges, or fight tooth-and-nail.
Kentucky's Democratic governor opted to embrace the law in his conservative state. He expanded Medicaid, accepting federal money to provide health care for those on the lower end of the income spectrum, and presided over the implementation of Kynect, the state exchange.
He won a second term in 2011, leaving office at the end of 2015.
Hillary Clinton over Vermont Sen. Bernie Sanders in the Democratic presidential primary and encouraged people to vote for her over Trump in the general election. Closer to the election, news reports
indicated Clinton was considering Beshear to serve in her would-be administration.
Just ahead of Trump's first joint Congressional address, Democrats announced he would deliver their response to Trump's State of the Union-style speech.
What has he said about Trump?
Until this rebuttal, Beshear will not have gone particularly far out of his way to criticize Trump, despite his vocal backing of Clinton.
He had strong words for the President, however, in the statement
announcing his response speech.
"Real leaders don't spread derision and division -- they build partnerships and offer solutions instead of ideology and blame," Beshear said. "President Trump would have people believe that all immigrants are criminals and that refugees are terrorists. But like my family, the vast majority of immigrants and refugees came to this country escaping poverty and conflict, looking for a better life and the opportunity to reach the American Dream."
House Minority Leader Nancy Pelosi praised Beshear and cited Kentucky's experience under Obamacare as a model for the nation, while a state Republican Party spokesman told CNN
at the time that it was "laughable" and called the notion that health care improved under Beshear a "myth."
What about Kentucky?
Born in Kentucky, Beshear offers a contrast with Trump, hailing from the kind of place the New York City-born real estate mogul has forged a deep connection with.
According to the Kentucky government's Energy and Environment Cabinet's final 2016 report
in conjunction with the Kentucky Coal Association, coal employment went from almost 18,000 people in 2008 to less than 10,000 by the end of Beshear's second term. As of 2016, the report says only 6,550 people were employed in coal.
However, the jobs picture under Beshear was not as bleak with seasonally adjusted unemployment rates generally tracking slightly above the national average, per the Bureau of Labor Statistics.
Politically, many of the Democratic wins under Beshear have been all but wiped out. Republicans control the governor's mansion, the state legislature and both Sen. Mitch McConnell -- who Beshear once unsuccessfully challenged -- and Sen. Rand Paul are Republicans. And, Trump won
all but two counties in the presidential election.
So Beshear comes from one of the places that helped build Trump's movement, and he has a particular story to tell, given his experiences there. And on Tuesday night, he will have to try to tell that story in an often strained format after Trump delivers a prime-time address with nearly the full weight of the legislative branch as his audience.