Democratic front runner Hillary Clinton just gained momentum over presumptive Republican presidential nominee Donald Trump in the polls. Clinton jumped 11 points ahead of him, according to a recent Washington Post-ABC News poll. And, she may have Bernie Sanders voters to thank for it.

Last month, 20 percent of Sanders supporters claimed they would vote for Trump if Sanders wasn't an option in November, but now that number is down to 8 percent, according to pollsters. What a difference a month makes.

Washington Post-ABC News Poll/The Fix - washingtonpost.com

We've seen this before.

This swing isn't entirely unexpected, according to the Washington Post. In 2008, when Hillary Clinton lost the Democratic party's nomination to then-presidential nominee Barack Obama, Clinton supporters initially balked at voting for Obama.

As evident in the graph below, many Clinton backers did a some flip flopping in the months preceding the election. In June 2008 a full 20 percent of Clinton backers hinted that they would vote for the Republican presidential nominee John McCain, but by October, that number shrunk to 14 percent, ultimately leading to a 7-point victory for Obama.

Washington Post-ABC News Poll/The Fix - washingtonpost.com

Why 2016 could be different.

While it took months for Clinton supporters to warm to Obama in 2008, the movement of Sanders backers to Clinton's campaign seems to be happening much faster this year.

It's only June — at which time 20 percent of Clinton supporters still opposed Obama in 2008 — and already only 8 percent of Sanders supporters still claim they will vote for the Donald. On top of that, 81 percent of Sanders backers are currently behind Clinton's campaign, which as the Washington Post article explains, is higher than the number of Clinton supporters (74 percent) who rallied to Obama at any point in the 2008 election.

What's the reason for the swift turnaround? For one, nearly 70 percent of Sanders supporters say they are "afraid" of the Republican party versus 55 percent of Clinton backers, who tend to be more moderate. Plus, while McCain may have initially seemed like a viable option for more middle-road Clinton supporters in 2008, Sanders supporters seem to have far less in common with Trump than they do with Clinton's platform this year.

Since this new poll occurred after Sanders's partial endorsement of former Secretary of State Clinton, it'll be interesting to see if more of his supporters will ditch Trump for Clinton if he chooses to fully endorse Clinton for president.