If you're looking for one Senate race that will most closely mirror the national mood on President Trump this November, the race in Florida might be it.

Gov. Rick Scott (R) announced Monday that he'll be challenging Sen. Bill Nelson (D) in what will be a titanic battle to try to make Florida's two U.S. Senate seats both Republican. Scott is well funded and well known in Florida, making him a serious challenger in one of the nation's most competitive and expensive states to campaign in.

But he's also got one potential weakness: Perhaps more than any other major Republican Senate candidate this cycle, Scott is uniquely tied to President Trump. He was one of Trump's first mainstream Republican supporters. Scott wrote an op-ed in support of Trump while Sen. Marco Rubio (R-Fla.) was still seeking the GOP nomination in 2016. Then Scott headed a super PAC that raised some $20 million for Trump's election campaign. He rarely criticizes the president.

After Trump won, he returned the favor by publicly urging Scott to jump into the race for Senate — making clear that he would help the Florida Republican every step of the way.

Trump urged Scott to enter the U.S. Senate race. (Michael Reynolds/EPA)

But being buddy-buddy with Trump could be the last thing Scott wants in this electoral environment. Trump won Florida by a little more than a percentage point in 2016, and if the election were held today, he might not be so lucky. Slightly more Florida voters disapprove of Trump's job so far as president (44 percent) than approve (41 percent), according to a Florida Atlantic University Poll in February.

Democrats have won a handful of local and state House elections in Florida in the era of Trump. And Democratic candidates to replace Scott as governor are already trying to outdo one another on who can be the most anti-Trump, banking on that as a winning argument for both the Democratic primary and the general election.

Democrats are also spending significant time and resources to register displaced Puerto Ricans to vote in November, reminding them that the Trump administration decided to end humanitarian emergency aid to the island after a devastating hurricane when many Puerto Ricans felt recovery still had a long way to go.

Trump, in other words, could be a liability in Florida more than in other states — and perhaps for no candidate as much as Scott. “Donald Trump's numbers in the state of Florida are abysmal and not improving,” Florida-based GOP strategist Rick Wilson told The Fix in March, adding that slumps in the stock market and in real estate often whack Florida's economy first and last the longest there.

So it didn't surprise political observers that Scott used some of his first comments about his Senate run to try to distance himself from the president. “I consider myself Rick Scott. I don’t consider myself any type of anything,” he told Politico on Sunday when asked if he considered himself a “Donald Trump Republican.”

But that may be too little too late. It's almost as though the powerful dynamics that launched Scott into office are reversing, said Steven Schale, a Florida Democratic strategist who watched almost helplessly as Florida turned against Democrats in 2010, 2012 and 2014 while President Barack Obama was in office. He said it didn't matter what kind of message candidates ran — the anti-Obama head winds were too strong to overcome.

There's evidence that's exactly what's happening in Florida now for the GOP. A Republican lost a competitive mayoral special election in 2017 in St. Petersburg despite basically ignoring Trump. A Democrat flipped a state House seat in Sarasota in February despite the district's support for Trump in 2016 and the fact that former Trump campaign manager Corey Lewandowski campaigned for the Republican. Pro-Trump and anti-Trump messages have been losers for Republicans this year, especially in Florida.

That should worry Scott, because no matter how good of a campaigner he is — and Republicans and Democrats in Florida alike say Scott could be formidable — it might not matter. The fact that he's a Republican in an anti-Republican environment might be too tough to overcome if the national mood holds — and his ties to Trump exacerbate that dynamic.

“If this turns into a referendum on the president, which the last three midterm elections have turned into,” Schale said, “… A lot of [undecided voters] will be showing up specifically to send a message to Trump, the same way they specifically sent a message to Obama.”

A Senate Democratic campaign aide noted that Scott, who has been governor of Florida since 2010, has never had to run for statewide office in Florida when the national mood has swung against his party. Scott came to prominence in the tea party wave of 2010, running against the party in the White House and Congress. He won reelection in another Republican election wave in 2014, though only by one point. This year is shaping up to be a new landscape entirely for Scott, one where he doesn't have a helpful boogeyman in the form of the opposing party's president.

None of this is to say that Florida's Senate race won't be competitive. In an election cycle during which Republicans are desperately trying to hang onto their slim 51-to-49 majority in the Senate, picking up a seat in Florida will be of utmost importance. And Senate Republicans are extremely happy with recruiting Scott to try to help them do that.

But for as strong of a candidate as Scott is, he has an Achilles’ heel that may be tough for him to overcome: his ties to the president.