He was a big feature of the 2020 presidential debate, and now Democrats are going to try to unseat Sen. Mitch McConnell, the most powerful Republican in Congress. They just recruited a candidate to do it: Marine veteran Amy McGrath, who announced her candidacy Tuesday morning. But even though McConnell (Ky.), the Senate majority leader, is unpopular in his state, it’s going to be an uphill battle for McGrath to persuade Kentucky voters to oust him and elect a Democrat instead.

Here's why:

Kentucky is a Trump state. They voted for Donald Trump over Hillary Clinton by 30 points in 2016.

McGrath has yet to prove that she can win in such an environment. She ran for Congress in 2018 seeking to unseat Rep. Garland “Andy” Barr (R) in a Lexington-area district. Her strategy was to try to win over rural Trump voters who had voted Democratic in the past. She spent about $8 million and lost by three points. The Associated Press’s Michael Tackett reports she was so confident she would win that she was writing her victory speech when the results were coming in.

But: Democrats say not to underestimate how unpopular McConnell is. Polls this year in Kentucky show that just over half of voters in the state disapprove of the job he’s doing, and independents are noticeably turned off by him. So if Republicans don’t turn out in a high number for McConnell and McGrath manages to rally independents, she could have a chance.

Her message is … confusing. McGrath knows she can’t alienate Trump voters. So what she’s trying to do instead is argue that McConnell is actually standing in the way of Trump’s agenda when it comes to things such as health care and jobs. “The things Kentuckians voted for Trump for are not being done,” she said on MSNBC. “He’s not able to get it done because of McConnell.”

The facts don’t quite bear that out. McConnell has cast himself as the “Grim Reaper” of Democratic legislation. He has been central to Trump’s biggest legislative accomplishments, including the tax-cut plan, and getting two conservative justices on the Supreme Court.

But: Democrats argue that McConnell’s experience is his downfall. Trump wants to drain the swamp; McConnell has been in office for more than 30 years and is the definition of the swamp, McGrath said. It helps that her background as a former fighter pilot is as far away from politics as one can get.

McConnell has been tried, and tested, and is battle hardened. This is not the first time that Democrats have tried to unseat McConnell. He beat Democrat Alison Lundergan Grimes, who spent $18 million against him, in 2014. He had a surprisingly close race in 2008 against a businessman, but he has survived for six terms — going on his seventh.

That’s in large part because McConnell knows his state and knows how to campaign and how to navigate around his unpopularity. It seems he has concluded that the key to his 2020 reelection is Trump. McConnell has recently avoided challenging Trump on any number of issues that he might have been more critical of last year.

Plus, we’ve seen over and over again in major Senate races how partisanship often overrides unpopularity. So does having decades of experience winning elections in your state. It’s how former Democratic Senate leader Harry M. Reid in Nevada kept getting reelected in a state that is much more swingy than Kentucky.

But: McConnell is a bigger name nationally than he has been in the past. The 2020 Democrats spent a significant chunk of their first presidential debate talking about how McConnell, as the leader of the Republican-controlled Senate, is standing in their way of passing legislation such as Medicare-for-all. His wife, Transportation Secretary Elaine Chao, has been in headlines for her stock holdings and allegations that her agency helped projects in Kentucky that are politically beneficial to McConnell.

There’s some compelling evidence that McConnell can be effectively used as a bludgeon outside of Kentucky, a kind of congressional boogeyman to motivate Democrats to turn out and vote in congressional races.

Democrats hope that can translate to Kentucky. A new group called Ditch Mitch has raised more than $1 million to unseat McConnell, well before McGrath got into the race.

She will need a lot more money than that, though, to unseat McConnell. And Senate Democrats’ campaign arm hasn’t decided whether to endorse her, let alone invest heavily in her.