TALLAHASSEE — This isn't the U.S. Senate campaign Patrick Murphy anticipated.
When he declared his candidacy in March 2015, the two-term Democratic congressman from Jupiter was poised to run for an open seat while Republican incumbent Marco Rubio sought the presidency.
Over the next 15 months, Murphy enjoyed the pole position in Florida's Senate race.
He was unofficially blessed as the Democratic establishment's pick to help the party win back control of the Senate.
Democratic figureheads and party loyalists showered him with endorsements and donations. He reliably led his primary opponents and consistently polled comfortably ahead in hypothetical matchups against five Republican hopefuls — each of whom failed to stand out in their own primary contest.
Entering this summer, Murphy had the potential to cap off a fierce primary battle with fellow U.S. Rep. Alan Grayson and then relatively coast through the general election to a seat in the U.S. Senate.
But Murphy's smooth ride was quickly upended.
Rubio re-entered the Senate contest in June after Republican leaders urged him to run again, giving Murphy stiffer competition for November. Murphy's campaign was also tarnished this summer by revelations that he embellished aspects of his academic and professional credentials.
Although Murphy secured a primary win Aug. 30 with 59 percent of the Democratic vote, and recent polls show him within a few percentage points of Rubio, Murphy's road to potential victory in November is now much harder.
He largely weathered the résumé controversy, but Republicans are using it against him in attack ads.
Even after months of campaigning, many likely voters still don't know who Murphy is or don't have an opinion of him, polls have shown. He's also dogged by criticism — even from within parts of his own party — that he's a "weak" candidate, or at least not one as strong as Democrats expected him to be.
"Democrats really blew it when it comes to recruiting in Florida," Chuck Todd, host of NBC's Meet the Press said on MSNBC the day of Florida's Senate primary. "They thought they had a half-decent candidate, and then he turned out to be problematic."
Meanwhile, Rubio carries the inherent advantage, even with his own faults and the vulnerability of having missed a number of Senate votes while he campaigned for president.
Incumbents generally don't lose. Over the last 12 years, Senate incumbents have won re-election more than 85 percent of the time. And in Florida, specifically, a U.S. senator hasn't lost re-election since Paula Hawkins lost to Bob Graham in 1986.
Nonetheless, Democratic insiders maintain Murphy is in good shape to unseat Rubio.
"Patrick has built a good campaign," said Steve Schale, a political consultant who isn't working with Murphy. "He's sort of done everything the right way; he hired smart people and he raised good money."
Because it's Florida, "no one is going to run away with this thing," Schale added, noting that the outcome will depend heavily on how much Murphy and Rubio can blanket the airwaves with ads and how well the top of each party's ticket fares in the presidential contest.
The night of the primary, Murphy went on the offensive, ramping up his earlier attacks on Rubio by blasting his attendance record and tying him to Republican presidential nominee Donald Trump. Rubio did the same by emphasizing Murphy's résumé inflation and labeling him as a "rubber stamp" for the policies of Hillary Clinton and President Barack Obama.
Murphy has altered his strategy for the general election, painting himself as the scrappy underdog against Rubio — a role familiar to Murphy from his first U.S. House campaign against a powerful tea party incumbent four years ago.
"I can almost promise you that we are going to be outspent in this election," Murphy said after his primary win. "But I'm not worried. I'm confident. We were outspent against Allen West. We've been down this road before. ... We won then and we'll win again."
Murphy started shifting his message, too, to portray a broader appeal to independents and moderates.
No longer is he relentlessly touting himself as a "progressive" as he did to fend off Grayson in the primary. His first TV ad of the general election — a positive-sounding attack ad against Rubio's attendance record — instead emphasized his "independence" and ability to work across the aisle, themes he used to win re-election in his moderate congressional district in 2014.
But there are growing indicators that Murphy might have to rely more on that personal political stock, rather than the national party's, in order to beat Rubio.
Other competitive U.S. Senate races have become easier — and less expensive — prospects for Democrats.
That good news for national Democrats actually has the potential of hurting Murphy in Florida, said Nathan Gonzales, national editor for the Rothernberg & Gonzales Political Report.
As the national landscape has evolved, there are now nine clear tossup races for Democrats to pick from and they no longer see Murphy as essential as they did just a few months ago.
"That has taken a lot of pressure off Democrats in Florida," Gonzales said. "Florida is not a must-win for Democrats to retake the majority."
That could draw resources away from Florida's contest to other states that are considerably less expensive to campaign in, like New Hampshire and Indiana.
The Democratic Senatorial Campaign Committee canceled the first week of a massive ad buy planned for Florida, saying it was shifting resources to use them closer to Election Day.
The DSCC said Florida "is clearly a competitive race and one that Democrats can win," but Republicans jumped on the news to declare Democrats were "bailing" on Murphy's "losing campaign."
The chance to take out Rubio — a potential GOP presidential candidate for 2020 — will keep Democrats watching Murphy's progress, said Larry Sabato, director of the Center for Politics at the University of Virginia.
"If internal polls show it to be competitive, Democrats will ramp up," Sabato said. "They would really love to knock off one of the Republicans' top contenders for the White House."
Contact Kristen M. Clark at firstname.lastname@example.org. Follow @ByKristenMClark.