There is much joy in liberal circles these days about the plight of the GOP and conservatism. Democrats now control the presidency, the House, and the Senate. President Obama's approval ratings are above 60 percent in most polls. The public is much more optimistic than it was at the end of last year. Meanwhile, the percentage of Americans identifying themselves as Republicans is at or near record lows.

These are undoubtedly heady days for Democrats and liberals, and they should enjoy them while they can. Moments like these can be fleeting in politics (less than five years ago, Republicans controlled all three branches of the federal government, a majority of governorships, and a plurality of state legislatures). It all depends on what unfolds. And on this point, it is worth keeping in mind the words of Lincoln.

In a letter, Lincoln engaged Williamson Durley on the matter of whether or not it was right to have cast a vote for the Whig Henry Clay in his presidential bid against James Polk (this account comes courtesy of Ronald C. White, Jr.'s excellent new biography A. Lincoln). Durley thought not; religious principles, Durley argued, forbade him and other champions of abolition from voting for Clay, a slaveholder who also opposed the expansion of slavery.

Using biblical imagery, Lincoln said of Henry Clay, “By the fruit the tree is to be known. An evil tree can not bring forth good fruit. If the fruit of electing Mr. Clay would have been to prevent the extension of slavery, could the act of electing have been evil?”

Set aside how Lincoln came to view some in the abolitionist movement — as people concerned more with being “righteous” than with winning and thereby advancing the anti-slavery cause. His deeper point, echoing the words of Jesus in Matthew chapter 7, is that acts have consequences — and those consequences, while not immediately apparent, become clear over time.

There is something for conservatives to learn from this as it relates to our present moment. President Obama is at the tree-planting stage of his presidency. The first 100 days have gone, by many measures, quite well. He is clearly a man in possession of some remarkable political skills, and it would be foolish to pretend he is not a formidable figure. Conservatives ought not commit the same error with Obama that liberals did with Reagan, which was to dismiss his gifts because they disagreed with his philosophy.

But eventually what Obama will be judged by are the fruits of his labor. And if the conservative critique on economics is correct, the emerging fruit will be bitter, and the public will eventually realize it. If his spending plans are as dangerous as we believe, if the extraordinary debt he is amassing is as threatening to economic prosperity as we say, and if his proposals really do harm growth and create a strong disincentive for the investing class, there will be a political cost to it all.

The danger, of course, is that a lot of damage is done between the time when the trees are planted and the fruit emerges. We saw this with the Great Society, in which even successful efforts to reverse certain programs took decades; and in some instances, the changes made by President Johnson became irreversible. That's why conservatives need to wage a vigorous, principled case against Obamaism, using “the accents of entreaty and persuasion” rather than “the thundering tones of anathema and denunciation” (to use Lincoln's words again) if they want to have an effect.

If, on the other hand, Obamaism is judged by the public to be a success rather than a failure — if strong economic and job growth occur, if inflation doesn't rear its ugly head, if civic order is strengthened, and if our national security is enhanced — that scenario would create challenges for conservatives. I have real doubts that Obama's proposals will succeed, since I believe they cut against the lessons of history, the laws of economics, and the rules governing human nature. But I'm certainly willing to assess and reassess things after a reasonable period of time. One thing conservatives should not be guilty of is anti-empiricism.

This observation, however, requires a caveat. It's quite possible, for example, that all of the liquidity in the system right now will spur temporary economic growth. In fact, it's hard to imagine that it won't. If it comes, Obama will, for a time, be hailed as a miracle worker. The test, of course, will be whether he has put in place policies that will, over the medium and long term, lead to economic growth, jobs, and prosperity. That will be the standard by which Obamaism will be judged.

With all that in mind, conservatives might consider pursuing several strategies at once. They should oppose policies on their merits and explain, in a reasonably intelligent and accessible fashion, why they do. Conservatives should also, and just as importantly, come up with a series of proposals and reforms that meet the challenges of this moment. They need to propose solutions that address the concerns in people's lives in a way that strikes them as relevant rather than out of touch. They need to provide a framework and governing narrative. It would also help if a compelling political figure emerged as the spokesperson for the cause. And in all of this, critics of Obama should embrace the virtue of patience.

Sometimes it's tempting to try to force events rather than allow them to come to you. Right now a lot of things are in flux in American politics; things that have been set in motion need to sort themselves out. A year from now the main problem facing our country may be in the arena of national security. It may be economic (deflation or inflation). It may be another. Circumstances will dictate a lot of what the public will be looking for. At this stage, we just don't know.

Conservatives should act with a sense of urgency and fight hard for the causes they believe in. But there is no need for desperation or despair. For one thing, the political mood of a nation can shift as quickly as cloud shadows. More importantly, if our underlying propositions are the right ones the public will not turn against them, at least for long. Americans are a deeply practical and results-oriented people, which is to say they hold a conservative view of the world. The job of conservatives is to be patient, intelligent, and cheerful advocates for their cause. Over time, things do have a way of righting themselves.