Hillary Clinton
Hillary Clinton has slipped in recent poll numbers in Colorado and Iowa, but has managed to keep her advantage over Republicans in VirginiaReuters

A poll released by Quinnipiac University reveals Hillary Clinton is losing her edge against Republican presidential hopefuls in three key swing states.

The swing state poll, which was released on 9 April, shows Clinton trailing behind Kentucky Senator Rand Paul in both Colorado (44% to 41%) and Iowa (43% to 42%). The likely Democratic candidate narrowly holds a lead over Paul in the state of Virginia (47% to 43%).

Colorado

According to the poll, Clinton also falls behind Florida Senator Marco Rubio (41% to 40%) and Wisconsin Governor Scott Walker (42% to 41%) in the Centennial State. The former secretary of state manages to tie former Arkansas Governor Mike Huckabee at 41% and leads Texas Senator Ted Cruz (42% to 41%), former Florida Governor Jeb Bush (41% to 38%) and New Jersey Governor Chris Christie (41% to 39%).

Clinton's negative favourability ratings in Colorado have increased since February to negative 41% to 51% favourability. According to Quinnipiac, Colorado voters distrust Clinton and believe that the controversy involving her emails is "very important" or "somewhat important" as an issue in their vote, at 51%.

Iowa

Clinton fares slightly better in the Hawkeye State, according to the poll. She edges nearly all candidates, except for Paul and Huckabee, who she ties with at 42%. The Democrat leads Christie (41% to 39%), Bush (41% to 40%), Rubio and Cruz (43% to 40%). Clinton's biggest advantage come against Walker at 44% to 40%.

The likely candidate also saw declines in favourability ratings in Iowa since February, with a split 45% to 47% favourability rating. Iowa voters, like their counterparts in Colorado, viewed Clinton as dishonest and untrustworthy, albeit at a smaller percentage rate. Voters were also less decisive regarding Clinton's email controversy.

Virginia

The Old Dominion continues to favour the Democrat, giving her an edge on all Republican likely candidates. Clinton edges Bush (47% to 40%), Christie (46% to 40%), Huckabee (48% to 40%), Walker (47% to 40%) and Rubio (48% to 40%). She holds her biggest lead against Cruz with 49% to 39%.

Clinton kept similar favourability ratings in Virginia, with a split 48% to 45% favourability rating. However, Virginia voters do view her as dishonest and untrustworthy, at 52% to 40%. Virginia voters also say that her email scandal is important to their vote at 51%.

The latest poll numbers prove to be a "boost" to newly announced presidential candidate Paul and a reason to worry for Clinton, Quinnipiac University Poll assistant director Peter A Brown said.

"Ominous for Hillary Clinton is the broad scope of the movement today compared to her showing in Quinnipiac University's mid-February survey," Brown said. "It isn't just one or two Republicans who are stepping up; it's virtually the entire GOP field that is running better against her. That's why it is difficult to see Secretary Clinton's slippage as anything other than a further toll on her image from the furore over her email."

Clinton has courted controversy lately after it was reported she used a private email account to send official emails during her time as secretary of state. Although she has not formally said she will be running in the upcoming election, she is expected to announce her bid soon.