President Barack Obama heads to the Midwest this week to return his vision for the economy to prominence ahead of this fall’s revived combat with Congress over the budget. How much of a head start he’ll get in shaping the standoff with Republicans will be known before his first speech.

The president is headed to Knox College in Illinois on Wednesday. On Tuesday, the Senate will take its first key vote on appropriations for the coming year. It’s very possible that just enough Republicans will break with their party leadership to form a coalition with the Democrats against the tight discretionary spending caps called for in the sequester.

The vote is about whether to break an initial filibuster and allow the first floor debate of the year on a fiscal 2014 appropriations bill, which most Republicans oppose because its $54 billion grand total would be 10 percent more than what the sequester is now allowing to be spent on transportation, housing and community development — and 15 percent more than what the House intends to spend.

As my colleague Niels Lesniewski has reported, Majority Leader Harry Reid has decided to abandon the customary strategy for moving spending bills in times of tight budgets, which is to seek relatively easy victories at the outset for the politically popular bills — covering defense and veterans programs — and hold off on the more polarizing domestic and social policy measures until the end.

He’s essentially challenging the GOP, from the outset, to cast votes that show their readiness to cancel the sequester so that both guns and butter can be funded at levels that don’t require such deep cutbacks.

And it looks as though he’s close to getting his way. Reid would need six GOP votes to break the filibuster, a strong suggestion of willingness to abandon the budget caps. There were six Republicans on Appropriations who voted to send the bill to the floor: Susan Collins of Maine, Thad Cochran of Mississippi, John Hoeven of North Dakota, Mark S. Kirk of Illinois, Jerry Moran of Kansas and Lisa Murkowski of Alaska.

If the filibuster isn’t broken, it would signal that few, if any, of the dozen regular spending bills are going to be passed by the Senate before the new budget year begins on Oct. 1. That would mean another year of status quo impasse between the generally spend-more Democratic Senate and the generally spend-less (except on defense) Republican House.

But if a bipartisan supermajority moves ahead with the budget-challenging spending levels, that would deliver a strong signal to Obama that he’s got an opening to make cancellation of the sequester a part of any year-ending budget deal. He also wants to include more tax revenue from the rich, a slowed trajectory for Medicare spending increases and a long-term rise in the ceiling for federal borrowing.

At Knox, where he also gave his first big economic speech as a senator in 2005, Obama is going to articulate those goals as a way  to achieve his vision for an economy that grows through an expansion of the middle class. That can’t happen, he’ll argue, unless debt ceiling and default fears are put to rest, entitlements are restrained and the federal government has latitude to invest in education, infrastructure, housing, manufacturing research and technology.

Republicans remain comprehensively opposed to Obama’s mix of spending investments and tax increases.

On CBS’ “Face the Nation” Sunday, Speaker John A. Boehner said the way to get the economy moving was to do more to restrain federal spending and regulation. “We’re squeezing the middle class,” he said, “and I would argue the president’s policies are getting in the way of the economy growing, whether it’s Obamacare, whether it’s all these needless regulations that are coming out of the government.”

As on the fiscal cliff earlier this year, and on immigration and student loans this past month, all eyes are on Republicans in the Senate.