Senate Majority Leader Harry Reid is shifting the chamber into campaign mode this week, bringing a mix of bills to the floor designed to highlight differences with the GOP while providing chances for some legislative accomplishments.

With just three and a half months before the midterm elections, Reid’s strategy appears to be as simple as it is traditional: Use much of the remaining legislative calendar to pursue “message bills” such as energy and campaign finance reform, while mixing in just enough doable measures (like a small-business jobs bill) to pad Democrats’ stats before the November elections.

“We definitely have an agenda for the rest of this work period that creates a sharp contrast between Democrats and Republicans,” a senior Democratic leadership aide said Friday.

It’s a legislative course that Democratic and Republican leaders alike have pursued for decades, particularly when their party is facing a difficult political climate as Democrats are this year.

One of the key aspects of Reid’s agenda strategy is to force votes on legislation that will create a clear contrast between Democrats and Republicans, even when he clearly does not have enough votes to break a filibuster.

To that end, the Senate on Tuesday afternoon is scheduled to vote on Democratic Conference Vice Chairman Charles Schumer’s DISCLOSE Act, which is designed as a legislative response to the Supreme Court’s landmark Citizens United campaign finance ruling earlier this year. The decision allows corporations and labor unions to spend unlimited funds on political advertisements, a practice that had previously been banned.

Although the New York Democrat has made key changes aimed at drawing out GOP support, thus far he has been unable to persuade moderates such as Sens. Susan Collins (Maine), Scott Brown (Mass.) and Olympia Snowe (Maine) to back the bill, while liberal Democrats have balked at its carve-out for the National Rifle Association.

Nevertheless, with most of the Democratic Conference behind the bill — and the media-savvy Schumer making the case that opponents are looking to give powerful interests an advantage over “average Americans” during the election — Reid sees it as a prime opportunity to hammer the GOP.

“This is a good issue for us. Don’t be surprised if you see it more than once,” a senior Democratic aide said. “There’s a clear contrast. Either you believe large corporate interests should control elections, or you believe the American people should control our elections.”

Similarly, Democrats see the pursuit of energy legislation, which also has no chance of passing, as a potential messaging win for them. The BP oil spill in the Gulf of Mexico has not only tarnished the oil giant’s image, but has also increased public skepticism of the industry in general. Democrats believe that they can use GOP opposition to an energy bill to tie Republicans to BP.

By opposing the legislation, Republicans “put themselves squarely on the side of BP, which isn’t a good place to be,” a Democratic aide said.

In addition to these message-based efforts, Reid is also looking to actually pass a handful of measures before the August recess in order to create some momentum going into the break and provide his candidates with accomplishments to tout during August.

One senior Senate Democratic source said leaders were looking for a way to bring up a Federal Aviation Administration authorization bill this week. Reid may try to shoehorn that debate in before his much ballyhooed “energy” debate on a narrowly focused oil spill measure.

The FAA bill is a particularly attractive measure for Democrats, in part because it is largely noncontroversial. Additionally, since it is a “message from the House,” Reid can avoid a time-consuming cloture vote to begin debate, limiting the amount of time the chamber will spend on it. And because Democrats have also been careful to insert several jobs provisions into the bill, it allows them to plausibly argue the reauthorization is a jobs bill aimed at righting the economy.

Sources said it was unclear Friday exactly when the Senate would finish up action on the small-business lending bill because several issues regarding the measure must still be worked out.

Like the FAA bill, the small-business bill represents legislation Democrats actually believe they have a chance of passing, despite a series of recent hiccups in the process that have slowed work to a crawl. But Democrats and Republicans alike believe Reid will ultimately find a way to move the measure out of the chamber, giving his Conference a much-needed economic win.

However, the timing of the small-business bill remains in flux. If Reid is unable to cement a deal on the small-business bill, he may turn to FAA as soon as procedurally possible — sometime late Tuesday or early Wednesday. But trying to do the FAA measure this week could push the debate on the oil spill bill into the week of Aug. 2, when Reid had hoped to take up and confirm the Supreme Court nomination of Elena Kagan.

A Republican aide rejected notions that Reid’s schedule is anything more than a sign of his poor management of the floor, pointing to his inability to move the small-business measure despite broad support for the bill.

“Sen. Reid has put the small-business bill on and off the floor so many times that even the president had to chime in [Friday] and demand action. I would hate to have to work in their press shop these days because it really steps on his ‘Republican obstruction’ messaging when he pulls it off the floor once or twice a week while his aides are blaming someone else,” the aide said.

“I know he’s disappointed about his national energy tax bill falling apart, but he doesn’t have to take it out on the poor small-business bill,” the aide added.