Rep. Patrick Murphy remains unknown, and that could be problematic for Democrats hoping to unseat Sen. Marco Rubio come Election Day.

A new tracking poll from conservative-leaning Associated Industries of Florida showed 51 percent of likely Florida general election voters said they either had no opinion or had never heard of Murphy.

The numbers might be troubling, but the survey suggests Murphy faces a significant hurdle in Democratic-leaning South Florida. In the Miami-Fort Lauderdale region, 22 percent of likely voters said they had no opinion of him, while 34 percent said they had never heard of him.

Murphy has struggled with name recognition for months. A Public Policy Polling survey in early September found 29 percent of Floridians had a favorable opinion of Murphy, while 24 percent had an unfavorable opinion. In that poll, 47 percent of Floridians said they didn’t have an opinion of the U.S. Senate hopeful.

A recent Florida Chamber Political Institute survey found 29 percent of Floridians polled said “never heard of” Murphy. That poll found 22 percent of Floridians had a favorable opinion of Murphy, while 24 percent had an unfavorable opinion.

The most recent AIF poll — completed Tuesday night, before much of the state shifted into serious storm preparation — showed similar results. The poll, obtained by FloridaPolitics.com, found 22 percent of Floridians had a favorable opinion, while 27 percent had an unfavorable opinion.

Unsurprisingly, Rubio is well-known throughout the state. Just 17 percent of respondents said they either had no opinion or were unaware of the Miami Republican. The survey found 40 percent of Floridians had a favorable opinion of him, while 43 percent had an unfavorable opinion.

The poll showed Rubio leads Murphy, 49 percent to 41 percent. Nine percent of Floridians said they were still unsure about who they would be voting for.

That eight-point lead is due in part to strong support among independent and Hispanic voters, more than half (51 percent) of which said they were backing Rubio. He also received strong support from white voters (57 percent) and voters between the ages of 50 and 64 (54 percent).

Murphy has strong support among black voters (73 percent), and leads among voters between the ages of 18 and 34 (48 percent).

When it comes to the presidential race, the AIF poll showed Hillary Clinton is edging Donald Trump, 44 percent to 41 percent. That’s within the 3.1 percent margin of error.

Libertarian Gary Johnson received 6 percent, while Green Party candidate Jill Stein received 2 percent support. Another 8 percent of Floridians said they were not sure who they were supporting.

Clinton has strong support among independent voters (44 percent), females (50 percent) and voters under 50 years old.