As President Obama prepares to deliver his State of the Union Address, there are many Democrats who wish that there was a tougher president sitting in the White House. After years of frustration, these Democrats yearn for a leader who can do more wheeling and dealing and who would engage in the hardball tactics that seem necessary to get things done.

If only Obama could be more like Lyndon Johnson. Almost everyone holds up Johnson up as the model of a president who knows how to make Congress work. Once reviled as the evil president who dragged the nation into Vietnam, Johnson is now memorialized as the magician of Washington who could do what everyone else found to be impossible.

The recent film “Selma” has come under fire for its portrayal of Johnson as disinterested in voting rights. Yet even this critical portrayal depicts LBJ as all-powerful. Rather than exploring why Johnson feared sending a bill to Congress, we see a president who is singularly making the decision to hold back legislation. If only Johnson had said yes, the rest would have been smooth sailing. This is what an imaginary world without Congress looks like.

For those longing for another tough Texan, there isn’t much optimism that we will see this from President Obama. “Obama is the anti-Lyndon Johnson,” Maureen Dowd wrote.

Yet the argument that Obama would be more effective if he acted like Johnson is premised on a powerful myth about Johnson—and, more importantly, a myth about what a president can do with a broken political environment. The truth is that all the political savvy in the world has rarely been enough to move a Congress when the legislators who controlled it fundamentally opposed the White House’s proposals.

The veneration of Johnson’s “treatment,” those moments when LBJ invaded the personal space of legislators to bully and seduce them, does more to obscure than illuminate how politics really works; the myth about LBJ over-emphasizes the capacity of “great men” to affect legislation by force of personality and undervalues the centrality of the political system in which a president must operate. The nation is continually searching for presidents who will somehow make Washington work by hook or by crook.

Even Lyndon Johnson wasn’t Lyndon Johnson. If we look closely at the critical years of his presidency, from January of 1964 to the middle of 1966—the period when Congress passed his bold domestic agenda that ranged from federal aid to education, immigration liberalization, environmental protection, Medicare and Medicaid, voting rights and civil rights and more—we can see a number of the crucial conditions that shaped Capitol Hill and allowed for a liberal moment to take place. When those conditions were gone, even Johnson couldn’t do much to make things move.

Social Movements. During the mid-1960s, social movement pressure was the driving force behind liberalism. Until the time of President John F. Kennedy’s assassination, politicians and experts were lamenting the dysfunctional Congress. Sen. Joseph Clark called Capitol Hill the “sapless branch” of the government.

This was a period when there was an ecosystem of liberalism that built pressure on Congress to take action on the vital social problems of the day. Public sympathy for JFK might have created some public support for the bills he never passed, but the interconnected world of grass roots activists, interest groups, intellectuals, and non-profit organizations gave liberalism its muscle. The civil rights movement was the most visible incarnation of this movement, but there were other important components as well including a robust union movement and liberal religious activism.

This movement created social pressure in congressional districts and gained media attention for key issues. It put pressure on both parties to pass legislation and did the gritty work of lobbying. It counteracted the procedural tactics of the conservative coalition.

One of the reason Midwestern Republicans agreed to end the Southern civil rights filibuster was that religious leaders, who held great sway in their communities, were aggressively lobbying them to come to the side of civil rights. The Senior Council of Citizens, a group created by organized labor, rallied Americans behind Medicare as the American Medical Association warned that the proposal was akin to “socialized medicine.”

“Selma” is spot on when it shows how instrumental the grass roots pressure was to getting movement from Washington. Johnson didn’t want to deal with voting rights in January 1965 because he feared that he lacked sufficient power to get everything he wanted from Congress and that another race-related bill would strengthen the hands of southern Democrats if moderates were too scared to vote for another bill. Selma was important to Johnson because it created unbearable pressure on Congress to do something immediately with or without him.

Large congressional majorities. Legislators love math. The reason is that the vote-count matters more than almost anything else on Capitol Hill. Before November 1964, liberals couldn’t move most of their bills through Congress. Southern Democrats teamed up with Republicans to block their bills. Southern Democratic committee chairs didn’t even let bills come up for a vote. In the Senate, James Eastland joked that he had a special pocket made to bury the bills he opposed.

Before the numbers changed, the civil rights movement had created enough pressure on Republicans to produce the Civil Rights Act. Congress passed the the War on Poverty in 1964 but it was still a small program, requiring a modest budget appropriation, and was sold as a conservative measure to allow people to become self-sufficient.

The real burst of legislation took place after the November election when Democrats gained huge liberal majorities in both chambers. Democrats had a 295-140 majority in the House and a 68 to 32 majority in the Senate. Democrats had more seats than at any time since 1936.  “There were so many Democrats,” noted one Illinois representative, “that they had to sit on the Republican side of the aisle.”

The importance of the majorities became clear after the midterm 1966 elections when they shrunk. Although Democrats continued to control Congress, the size of the conservative coalition had grown substantially.

Johnson was not effective any longer. In the coming years, Congress would only pass a handful of Johnson’s proposals and conservatives would turn the attention to the issue of rising deficits, inflation, and budget cuts. “Master of the Senate!” Johnson bitterly complained about everyone who thought he could do whatever he wanted, “I’m not master of a damn thing . . . We cannot make this Congress do one damn thing that I know of.”

Cooperative opponents. Without Republicans who would vote for his bills, Johnson’s Great Society would never have been so great. On many of the key bills from this period, such as the Civil Rights and Voting Rights Acts, as well as Medicare and Medicaid, Republicans were vital in moving legislation. Between mid-February and early March, Attorney General Nicholas Katzenbach and Republican Senate Minority Leader Everett Dirksen conducted secret negotiations over the basic framework for a voting rights bill. After hours of drinking bourbon, these men virtually reached an agreement before the famous marches actually started. Johnson was still not prepared to send a bill to Congress, but much of the hard legislative work had been done.

Bipartisanship did not come easy. Besides movement pressure, bipartisanship was also the result of the 1964 election. Barry Goldwater, with his rightward campaign, did so poorly that most Republicans were scared to do anything that made them seem to be like him. One Republican commented, “After this election, the conservatives simply are not entitled to be heard any more.”

Corrupt bargain. Many people like to quote the famous statement that LBJ made to his biographer Doris Kearns Goodwin: “That bitch of a war killed the lady I really loved—the Great Society.” The quote captured how many Americans think of Johnson: the brilliant mastermind of domestic policy slipped and allowed Vietnam to overcome his accomplishments.

Yet the expansion of America’s role in Vietnam was part of a bargain that LBJ made to clear the domestic playing field. During August 1964, when Goldwater was attacking Johnson for being weak on defense, the president tried to shore up his hawkish credentials by requesting from Congress the Gulf of Tonkin Resolution that gave him blanket authority to use force in the region.

Throughout the next two years, Johnson stood firm on Vietnam even as top Democrats warned him that the conflict would turn into a quagmire and destroy all the rest of his legacy.

The escalation of the war gave him political wiggle room to move his domestic policies and insulated him from conservative attack on national security issues. But the bargain came at a cost. The decision opened up terrible divisions within the Democratic Party. The budget also ballooned as a result of the war and forced the president into a “guns or butter” decision when it came time to reduce deficits.

It is time to stop exaggerating what Johnson could do and instead turn our attention to how Americans changed Congress to allow someone with his vision to succeed. We need to move beyond fetishizing presidential power, something that LBJ understood. “Power, the only power I’ve got is nuclear and I can’t even use that!”

The truth is that not a lot will get done in the next few years because Obama doesn’t have many cards to play against the Republican Congress. If Democrats would pay closer attention to how citizens have pressured Congress into passing liberal reform, only then would they understand what is needed to pave the way for an ambitious president.

Julian E. Zelizer is a professor at Princeton University and a fellow at the New America Foundation. He is the author of “The Fierce Urgency of Now: Lyndon Johnson, Congress and the Battle for the Great Society” (Penguin Press).