The list of liberal laments about President Obama keeps getting longer: He extended the Bush-era tax cuts for the wealthy.
Health-care reform didn't include a public option. In the frantic final hours of the budget negotiations, instead of calling the GOP's bluff, he agreed to historic cuts in progressive programs.
And recently, in response to conservatives' focus on the deficit, Obama said that we have to "put everything on the table."
What is the problem here? Is it a lack of leadership from the White House, a failure to out-mobilize the Tea Party or not enough long-term investment from liberal donors?
The real problem isn't a liberal weakness. It's something liberals have proudly seen as a strength - our deep-seated dedication to tolerance.
In any given fight, tolerance is benevolent, while intolerance gets in the good punches.
Tolerance plays by the rules, while intolerance fights dirty. The result is round after round of knockouts against liberals who think they're high and mighty for being open-minded but who, politically and ideologically, are simply suckers.
Social science research has long dissected the differences between liberals and conservatives.
Liberals supposedly have better sex, but conservatives are happier. Liberals are more creative; conservatives more trustworthy.
And, since the 1930s, political psychologists have argued that liberals are more tolerant.
Specifically, those who hold liberal political views are more likely to be open-minded, flexible and interested in new ideas and experiences, while those who hold conservative political views are more likely to be closed-minded, conformist and resistant to change.
As recently as 2008, New York University political psychologist John Jost and his colleagues confirmed statistically significant personality differences connected to political leanings.
Brain-imaging studies have even suggested that conservative brains are hard-wired for fear, while the part of the brain that tolerates uncertainty is bigger in liberal heads.
Dissecting Obama's negotiation strategy in the budget fight, Paul Krugman wrote in the New York Times, "It looks from here as if the president's idea of how to bargain is to start by negotiating with himself, making pre-emptive concessions, then pursue a second round of negotiation with the G.O.P., leading to further concessions."
The Washington Post's Ezra Klein has criticized Obama for similarly failing to take a strong position on energy policy. But perhaps the president is only playing out the psychological tendencies of his base.
In the weeks leading up to the budget showdown, the Pew Research Center found that 50 percent of Republicans wanted their elected representatives to "stand by their principles," even if it meant causing the federal government to shut down.
Among those who identified as Tea Party supporters, that figure was 68 percent. Conversely, 69 percent of Democrats wanted their representatives to avoid a shutdown, even if it meant compromising on principles.
With supporters like that, who needs Rand Paul?
The Opinion section is produced by the Editorial Department to foster discussion about key issues. The Editorial Board represents the institutional voice of the Star Tribune and operates independently of the newsroom.