Former Republican Gov. Larry Hogan made a surprise, last-minute entrance into the race for Maryland’s open U.S. Senate seat on Friday — upending the balance of the campaign.

So far the race had been mainly a Democrats-only affair, with U.S. Rep. David Trone and Prince George’s County Executive Angela Alsobrooks duking it out in that party’s primary. Now the Republican primary has a star, too, with Hogan’s name recognition and campaign skills.

So what happens now that Hogan is in the mix? We have some questions that we’ll be watching as the campaign season unfolds, first with May’s primaries and then with the November general election.

Why did Hogan change his mind about the Senate?

Hogan repeatedly — and really, we do mean repeatedly — shot down any suggestions that he’d be a good candidate for the U.S. Senate. This dates back to 2019, when national Republican leaders began to court Hogan to challenge U.S. Sen. Chris Van Hollen, a Democrat, in the 2022 election.

“I have no interest in the Senate,” Hogan told The Baltimore Sun in 2019. And again to Politico in 2022: “As I have repeatedly said, I don’t aspire to be a United States senator and that fact has not changed.”

Hogan had often said that he didn’t want to be part of the gridlock and grandstanding in Washington, and preferred not to be just one of 100 votes. So his about-face on Friday took many by surprise.

Could Mitch McConnell be the one who changed Hogan’s mind? Reports emerged Friday afternoon that McConnell, the leader of Senate Republicans, and Sen. Steve Daines of Montana, who leads the National Republican Senatorial Committee, worked to persuade Hogan.

“I enjoyed conversations we’ve had with Larry over the last week. He’s extraordinarily popular. To be competitive in a blue state like that is quite a boost for us,” McConnell told The Hill on Friday.

Daines issued a statement that didn’t address his role in the matter, but praised Hogan: “Governor Hogan is a great leader for Maryland, and that’s why he remains overwhelmingly popular in the state. We look forward to welcoming him to the United States Senate.”

Can Hogan win in the general election with Donald Trump on the same ballot?

It’s no secret that there’s no love lost between Hogan and former President Donald Trump.

Hogan did not vote for Trump in either 2016 or 2020, and the two clashed over the handling of the coronavirus pandemic. Hogan has pointedly separated himself from the Trump-fueled, Make-America-Great-Again wing of the Republican Party.

When Hogan ran for reelection in 2018, some thought he might be dragged down by Trump’s unpopularity in Maryland. But Hogan withstood the Trump effect, handily winning reelection in a year that was generally bad for Republicans.

Hogan’s and Trump’s elections were never on the same cycle before, and now their names could appear on the same general election ballot, should they each win the Republican nomination for their respective races.

Which Republican voters will turn out to the general election: MAGA-motivated Trump supporters, who might not fill in the bubble for Hogan? Hogan-wing Republicans who might need an extra push to vote?

There’s also the matter of the independent and Democratic voters who crossed over to support Hogan in his last two elections. Many of those voters liked Hogan’s brand of Republicanism but really dislike Trump’s. Will they offer the same support to Hogan again, now that his election could swing control of the Senate and bolster a national Republican agenda?

How will this change the calculations for Democratic candidates?

It took almost no time at all for the leading Democratic contenders to jump on the Hogan news and start attacking him.

Both Alsobrooks and Trone issued fiery statements and aggressive fundraising appeals, casting Hogan as an anti-abortion foe who needs to be defeated.

Is this a sign that the two of them will act as if they’re running against Hogan, instead of running against each other? Will they shift their messaging to how each one is better-positioned to defeat Hogan in the general election?

And will Democratic primary voters worry about who is most electable against Hogan? Trone has handily won Maryland’s most competitive House district; is that a winning argument for the general election? Can Alsobrooks argue she’s the only woman in the race and that Trone and Hogan are two sides of the same coin?

Democrats also have to recalculate their finances. When there were no experienced or well-funded Republicans running, Democrats could rest assured that the primary winner — whether it would be Trone or Alsobrooks — could easily coast to victory in the general election.

Now they’ve got a formidable Republican opponent on their hands.

What will the Republican primary results tell us about the allegiances of the party?

Plenty of Maryland Republicans have expressed frustration with Hogan, arguing that he’s not conservative enough and that he opposed Trump, the de facto national leader of the party.

The state party leadership skews MAGA, with Freedom Caucus member U.S. Rep. Andy Harris as the party’s highest-ranking elected official, and his wife, Nicole Beus Harris, as chair of the party.

And two years ago Hogan’s hand-picked successor in the governor’s race was upended in the GOP primary by Dan Cox, a Trump-backed state delegate.

Will Maryland Republicans turn out to vote for Hogan in the May primary? Or will a significant number of primary voters pick from among half a dozen other candidates, all with little money, name recognition or chance to win in the general election?

Pundits (and Democrats) believe that Hogan will likely win the primary election. But the margin of victory and the level of turnout could given an indication of how strong — or weak — the party support is for Hogan.

How well will Democrats motivate their voters for the general election?

This fall’s general election was shaping up to be a relatively sleepy one, at least when it comes to contested races.

President Joe Biden is a cinch to win Maryland in his reelection bid, and until Friday, Democrats thought their Senate chances were just as easy. Baltimore voters are electing a mayor and members of the City Council, but Democrats are so dominant that Republicans don’t even enter some races in the general election.

School board races could have been the most competitive races on the ballot.

When elections seem to be a foregone conclusion, sometimes voters stay home.

The one item on the ballot likely to energize Democrats is a question to amend the state’s constitution to guarantee the right of reproductive choice, further protecting legal abortion care in the state.

Now with a competitive Senate race on their hands, Democrats will need to turn out their voters to win. The Democratic Senatorial Campaign Committee immediately jumped into action on Friday, pushing out anti-Hogan talking points. It’s worth watching to see how much more national attention and money the race draws.