Salena Zito

For a striking number of Democrats, May 31, 2008, is a day that lives in infamy.

It marked the moment that the national party’s rules committee dealt a deathblow to Hillary Clinton’s bid to win the presidential nomination over Barack Obama.

The committee, weighted with Obama loyalists, issued a unanimous decision amid whispered back-door deals.

The date “will not be forgotten,” according to Gayle Allegro, a Democrat from Pine Island, Fla. – which is why Allegro was frosted by last week’s announcement that Bill Clinton will be the keynote speaker at the Democrats’ national convention next month.

“If Obama and his crew think that having Bill Clinton give a speech is going to sway all the Democrats that left the party in 2010 or just slipped into the shadows, they are mistaken,” she said.

“Do they really think we are that stupid, that we don't see what is going on?”

Allegro, 60, is one of those women who break glass ceilings. She has lived in Europe, North Africa and Israel, and she was one of the first women to work as a laborer on the Alaska oil pipeline while earning a master’s degree in economic geology.

In 2008, most Democrats sucked up their sense of personal loss regarding Hillary and voted for Obama because the idea of handing Republicans another four years in the White House was just too awful to bear, said Lara Brown, an electoral-college expert at Villanova University.

"Nevertheless, they had reservations about Obama's leadership skills and experience," Brown said.

By 2010, that allegiance waned and Clinton Democrats were the deciding factor that removed Democrats from power in the U.S. House, closed the margin in the U.S. Senate, and flipped state legislatures and governor’s mansions to Republicans across the country.

Now, on the threshold of the 2012 election, many are still angry with their party – anger that mirrors how conservatives felt in the 2006 Bush midterm election and the 2008 general election. It is anger enough to not vote, or to vote for the opposing team.

To understand why, you must understand their roots.

In 2004, Bill Clinton loyalists, distraught over Democrat John Kerry's defeat, hunkered down and planned for the next presidential election.

They fortified themselves with a few thoughts: Hillary would be the nominee in 2008, and Barack Obama's 2004 convention speech proved the party had a bright centrist future because both Hillary and Obama were pragmatists.

They didn't plan on Howard Dean supporters (including the "Netroots" and ideological progressives) believing that Kerry lost because he wasn't liberal enough.

Salena Zito

Salena Zito is a political analyst, reporter and columnist.