Imagine him in the last week of his life, 150 years ago this month. Shuffling, clothes hanging loosely on the 6-foot-4-inch frame, that tinny voice, a face much older than someone of 56. “I am a tired man,” he said. “Sometimes I think I am the tiredest man on earth.”

Springtime in Washington, lilacs starting to flower. The Capitol Dome finally free of its scaffolding. His month began in triumph against the largest slaveholding nation on earth. Richmond fell and was set afire by its retreating residents. On April 4, Abraham Lincoln, with his 12-year-old son, Tad --- his birthday! --- walked the smoldering shell of the rebel capital, walked a mile or so, pressed by a throng of liberated blacks, to sit as a conqueror in the seat of the Southern White House.

“No day ever dawns for the slave,” wrote a man who had once been owned by a fellow man. In Richmond, thereafter, all days had dawns.

On the dawn of his final day, April 14, Lincoln rises as usual at 7 a.m., breakfasts on coffee and an egg. He meets with his cabinet, confers with an ex-slave, lunches with the unpredictable Mary Todd. They have plans to attend “Our American Cousin.” In the box at Ford’s Theater that evening, a white supremacist fires a single shot from a Derringer. The bullet penetrates Lincoln’s brain and lodges just behind his right eye. The most significant casualty in a war that took more lives than any other in the nation’s history dies the next morning . the first president to be murdered.

Now think of the legacy on this anniversary of the American passion play. Think of free land for the landless, the transcontinental railroad, the seeding of what would grow into national parks, the granting of human rights to people who had none.

And think of how much the party of Lincoln has turned against the expansive political philosophy of Lincoln. Not the emancipation of four million people . Northern Democrats who died on southern battlegrounds, and certainly the Republicans who held power then, get their share of credit for ending the Original Sin of the United States.

But beyond: Could the Republicans who control Congress in 2015, the party of no, ever pass a Homestead Act? That law, which went into effect the very day, Jan. 1, 1863, Lincoln’s wartime executive order to free slaves in the breakaway states did, carries a clause that very few Republicans would support now.

Former slaves, “famine Irish,” Russian Jews, single women, Mexicans who didn’t speak a word of English --- all qualified to claim 160 acres as their own. You didn’t have to be a citizen to get your quarter-square-mile. You just had to intend to become a citizen.

In that sense, the Homestead Act was the Dream Act of today. It had a path to citizenship and prosperity for those in this country who were neither citizens nor prosperous.

Consider the vision to stitch a railroad from east to west, an enormous tangle of infrastructure. In 1862, Lincoln signed legislation spurring construction of the transcontinental railroad. That same year, he approved a bill that led to the creation of land grant colleges.

Today, Congress will not even approve enough money to keep decrepit bridges from falling down, and has whittled away funds to help working kids stay in college. It’s laughable to think of Republicans’ approving of something visionary and forward-looking in the realm of transportation, energy or education. Government, in their minds, can never be a force for good.

In 1864, Lincoln signed a bill that allowed California to protect the Yosemite Valley and the Mariposa Grove of giant Sequoias --- wild land that would eventually become part of the National Park system. Republicans of today are openly hostile to conservation, a largely Republican idea.

The great, nation-shaping accomplishments of Lincoln’s day happened only because the South, always with an eye on protecting slavery and an estate-owning aristocracy, had left the union --- ridding Congress of the naysayers.

Today, the South is solidly Republican and solidly obstructionist. The party is also solidly white. No, they’re not slave-apologists, though many fail to recognize the active, toxic legacy of the Confederacy. And no, their insults of President Obama --- calling him a king, an incompetent, an outsider, echoing some of the slights against Lincoln --- do not in any way make Obama the Lincoln of today.

But you can say this with certainty: what unites the Republican Party, on this 150th anniversary of the murder of Lincoln, is that they are against the type of progressive legislation that gave rise to their party. Lincoln is an oil painting in the parlor, to be dusted off while Republican leaders plot new ways to kill things that he would have approved of.

Nothing in politics is static. Things will change. Party philosophies will flip, new alliances will emerge. What we know for sure again comes from Lincoln: “Fellow citizens, we cannot escape history.”