A new poll shows that the gap between former Secretary of State Hillary Clinton and real estate mogul Donald Trump is starting to narrow.

A Reuters/Ipsos poll taken from July 15-19 has Clinton at 43 percent and Trump at 36 percent, which is still a decent-sized lead for Clinton but a sharp decrease from the 15 percent lead she had in the July 10-14 Reuters/Ipsos poll.

The sample size of the poll consisted of 1,069 voters and a margin of error of 3 percent.

While the poll has not been included in the RealClearPolitics polling average, Clinton currently only has a 2.7 percent lead in the RCP average, 43.8 percent to 41.1 percent:

Before Trump supporters get too excited, it's important to keep one thing in mind:

That's a consistent theme throughout the polls in the RCP averages. Reuters attributes Clinton's decreasing lead to a decreasing amount of people choosing neither candidate. The Hill attributes the tightening polls to the Republican National Convention and FBI director James Comey:

The poll comes amid the weeklong Republican National Convention, which has seen Trump become the party’s official presidential nominee. Political parties typically see a bounce in the polls during and immediately after their conventions.

Clinton’s lead appears to have slipped across polls since FBI Director James Comey revealed his findings in the investigation into her private email server. The FBI did not recommend an indictment but did sharply criticize the former secretary of State as "careless" while in office

They are certainly all factors, but the biggest factor of all is that Clinton is a terrible presidential candidate, as Shapiro has documented here.

The only reason Clinton even still has a lead is because Trump also happens to be a weak candidate. If he is serious about winning the election, Trump should give people a reason to vote for him rather than simply voting against Clinton to sway the people who are choosing neither candidate, which could end up being the difference in the election.