The email controversy surrounding former Secretary of State Hillary Clinton is cutting into the likely 2016 Democratic presidential candidate’s leads in crucial swing states over her potential Republican rivals, a Quinnipiac University poll released Tuesday finds. Clinton trails former Florida Gov. Jeb Bush in his home state, while Kentucky Sen. Rand Paul is besting her by one percentage point in Pennsylvania after she led him by 19 points there last month, the survey showed.

Last month’s Quinnipiac Poll found Clinton tied with Bush in Florida, but he now leads her in the Sunshine State, 45 percent to 42 percent. No candidate has won the presidency without winning at least two out of the three crucial swing states in Florida, Ohio and Pennsylvania.

Since the email controversy surfaced earlier this month that revealed Clinton exclusively used private email to conduct State Department business, public confidence in her honesty has dropped. Half of Florida voters surveyed in the Quinnipiac Poll said she is not honest and trustworthy, while a plurality of Ohio and Pennsylvania voters said the same. A Fox News poll conducted earlier this month found only 44 percent of voters nationwide said honesty is a trait that describes Clinton.

"The good news for Hillary Clinton is that the email controversy has not done huge violence to her presidential chances. But the matter is taking a toll on the former secretary of state's public image," said Peter A. Brown, assistant director of the Quinnipiac Poll. "On the plus side, Secretary Clinton is considered a strong leader -- a key characteristic for voters when picking a president, more so than her leading, but lesser-known, potential GOP opponents. But about half the voters in all three states question her honesty and trustworthiness.”

Of all three swing states polled, Clinton has a lead over her closest Republican rival in just one: Ohio. She leads Paul 46 percent to 41 percent in that state, a dip from the 12-point lead she had over the Kentucky senator last month. About one in four Ohio voters said she hasn’t given satisfactory answers to her email practices, which she said were for “convenience.”

More than half of Pennsylvania voters said that “serious questions remain” about Clinton’s emailing, while 52 percent said the email issue is important in deciding whether they will vote for the former secretary of state. The controversy has hit Clinton the hardest in Pennsylvania out of the three swing states. She led Paul, 53 percent to 34 percent, in February, but now Paul leads her 45 percent to 44 percent.

"A red flag in blue state Pennsylvania: Hillary Clinton, seemingly invincible before the email scandal, ends up tied with Rand Paul," said Tim Malloy, the poll’s assistant director. Pennsylvania has not gone Republican in a presidential election since 1988.

Clinton maintained leads over other possible Republican rivals in the latest poll.

The poll was conducted between March 17 to March 28 and surveyed 1,087 Florida voters, 1,077 Ohio voters and 1,036 Pennsylvania voters. It has a margin of error of plus-or-minus three percentage points.