President tries to overshadow GOP field -- again Continuing his occasional tradition of making a big splash on the same day as a milestone in the Republican primary battle, President Obama is planning a major economic speech focused on tax fairness Tuesday. That just so happens to be the same day GOP frontrunner Mitt Romney -- who has faced a barrage of attacks from Democrats and some Republicans about his wealth and relatively low tax rate -- will try to wrap up the race with a win in the Wisconsin primary. At a lunch sponsored by the Associated Press in Washington, Obama will deliver what senior administration officials are billing as a major speech laying out what he sees as the important choices facing the country on the economy. The primary theme of the speech will be overall fairness in the tax code, which is shaping up to be the central focus of Obama's re-election effort. It's a message the president first previewed about everyone paying their "fair share" during a heavily-watched speech in Kansas late last year, followed by a call to action on the same issue in his January State of the Union Address. "Now, you can call this class warfare all you want," Obama said on Jan. 24. But asking a billionaire to pay at least as much as his secretary in taxes? Most Americans would call that common sense. Senior administration officials say Obama will spend more time on Tuesday discussing the so-called Buffett Rule, which is his plan to institute a tax surcharge on millionaires. He is also expected to spend some time attacking changes to Medicare laid out in a budget plan authored by House Budget Chairman Paul Ryan, R-Wis. A spokesman for Ryan, who has already faced heavy criticism from the White House for the most recent version of his budget plan, fired back in advance of the president's Tuesday speech. "For four years the president has refused to honestly confront the most predictable economic crisis in our history," Ryan spokesman Conor Sweeney said on Monday. Instead, he has accelerated the nation toward this looming debt-fueled crisis with reckless budgets, always accompanied by partisan speeches that seek to divide the nation in order to distract from his legacy of broken promises. If he thinks there is no political price to pay for this total abdication of leadership, he is due for a rude awakening. Senior administration officials say Obama is taking particular aim at Ryan because if any of the Republican presidential candidates are elected, they would sign his budget plan into law. Ryan is also front and center because late last week he endorsed Romney ahead of Tuesday's primary in the House Budget chairman's home state of Wisconsin. Obama has occasionally tried to make a big splash around important milestones in the Republican presidential primary battle. After not holding a news conference at the White House for months, the president held one on March 6, which just so happened to be Super Tuesday. On Feb. 28, the same day as the primary battle in Romney's original home state of Michigan, Obama delivered a rousing speech at a United Auto Workers conference in Washington about how he saved the industry over the GOP front-runner's objections. Without naming Romney, Obama referenced the Republican candidate's 2008 op-ed headlined "Let Detroit Go Bankrupt" in the New York Times. "Some politicians even said we should "let Detroit go bankrupt!" " Obama said to boos from the auto workers. You remember that? Obama added: "Think about what that choice would have meant for this country, if we had turned our backs on you, if America had thrown in the towel. GM and Chrysler wouldn't exist today.