(CNN) Expect to see a whole lot of President Barack Obama this campaign season as he works to spell out what he sees as the stakes in the 2016 election and tries to defend his legacy.

As he approaches the end of his term in the midst of an election year that has been defined by heated, often controversial rhetoric coming from the leading Republican candidates, like GOP front-runner Donald Trump, the President is vowing to do all he can to make sure a Democrat replaces him at 1600 Pennsylvania Avenue. He also wants to retake the Senate and win more seats in the House of Representatives.

So far, he has headlined 35 fundraisers since the 2014 midterm elections and he has already endorsed 10 candidates at the state level, according to the Democratic National Committee.

"The President has been clear that as we get closer to the general election, it will become even more important that the American people understand what is at stake," said White House Deputy Press Secretary Jennifer Friedman. "Do we continue to build on the policies that reward hard-working American families, advance our economic and national security, and address challenges for future generations, or do we stop in our tracks, reverse our progress and move in the wrong direction? This is a choice that the President does not take lightly, and is something he will lay out for the American people with increased frequency in the weeks and months ahead."

Obama has telegraphed his desire to play an active role both at home in Washington and on the stump, telling the crowd at an Dallas fundraiser last week he could not be prouder of what he has accomplished and, "We're going to run through the tape."

He is eager to protect and defend his legacy, pointing to policies like the Affordable Care Act, his biggest domestic achievement, which he boasts has provided 20 million Americans with insurance coverage and which congressional Republicans have voted some 60 times to repeal. Republicans also fought vigorously against the Iran nuclear deal and many oppose his efforts to normalize relations with Cuba, a move that will get a big boost when he becomes the first president to visit the island in almost 90 years this weekend.

Trade deals, environmental and financial regulations are other accomplishments the President wants to protect. The fight over his Supreme Court nomination, with Senate Republicans vowing to block Merrick Garland, highlights the significance of regaining control, Obama said.

"We got to have not just a Democratic president who can continue the legacy that we built together over the last 7½ years, but we've got to have a Senate that is a partner in this process," he told supporters in Dallas last weekend. "And I can list a whole bunch of reasons for why that's so important. It turns out that because of the untimely death of Justice Scalia -- and obviously we grieve for his family -- but the behavior of the Senate since then, I think, gives you a pretty good reason of why we think the Senate is so important."

Whomever the Democratic nominee is, they will need the backing of the broad coalition of young voters, blacks, Hispanics and women that then-Sen. Obama brought out in 2008. Democrats are banking on Obama's popularity: He has long polled well within his own party, and a recent Gallup Poll shows his approval rating nationwide has ticked up to 50%, far higher than his predecessor George W. Bush (32%) at the same time in his presidency.

In fact, while Bush endorsed Arizona Sen. John McCain in 2008, he did no campaign rallies that year, according to longtime CBS White House Correspondent Mark Knoller, who keeps extensive records of presidential activities from golf outings to stump speeches.

The enthusiasm gap

The move to use Obama frequently on the stump comes as data from the states that have held primaries and caucuses so far indicate a huge enthusiasm gap. Democratic turnout has fallen in several key states compared to 2008 -- from low single digits in Illinois (2%) and Florida (3%) to even more troubling double-digit heights in Missouri (24%), North Carolina (30%) and Ohio (49%). Meanwhile, Republican voter turnout has jumped double digits in each of those states, rising some 75% in the must-win state of Ohio.

Obama is already working to boost enthusiasm among Democrats, calling on them to "get to work" alongside him to ensure victory in November.

"I'm absolutely convinced that we will have a Democratic successor as president," the President said at a DNC fundraiser in Austin, Texas, last week. "I believe we will take back the United States Senate. I think we will make real progress with respect to the House. But it depends on people feeling as if that can happen, and being engaged and working just as hard and just as full of hope as they did in 2008. And that's going to depend on me, but it's also going to depend on you. It's going to depend on each of us."

Vice President Joe Biden will also stump for the Democratic nominee in states where he can be helpful, reprising the role he played in 2008 when he was dispatched to help woo white working-class voters in states like Pennsylvania, and he hopes to help Democrats retake the Senate, too, planning to attend events in Ohio and Washington state next week, according to his aides.

The President has already been vocal about the tone of the presidential race so far, particularly on the Republican side, touting the need for inclusiveness rather than divisiveness in politics.

"The longer that we allow the political rhetoric of late to continue and the longer that we tacitly accept it, we create a permission structure that allows the animosity in one corner of our politics to infect our broader society," he said on Capitol Hill this week. "And animosity breeds animosity."

And while Trump gets much of the attention, Obama has not limited his criticism to the bombastic billionaire, blasting Texas Sen. Ted Cruz for saying he would carpet-bomb ISIS.

The President and first lady Michelle Obama voted absentee in the Illinois primary, but the White House declined to say for whom they cast their ballots. But officials have weighed in on a report in The New York Times that said the President privately told donors it was nearing the time when Bernie Sanders' campaign would end and that the party must soon come together behind Hillary Clinton -- a line seen as him putting his finger on the scale for Clinton. Press Secretary Josh Earnest vehemently denied the report.

"I was there for the fundraiser and I was there for the part where this conversation occurred," Earnest said Thursday. "What I'll just say in general is that President Obama made a case that would be familiar to all of you, which is that as Democrats move through this competitive primary process, we need to be mindful of the fact that our success in November in electing a Democratic president will depend on the commitment and ability of the Democratic Party to come together behind our nominee. And the President did not indicate or specify a preference in the race."

"In fact," Earnest continued, "the President pointed out something that he's pointed out to all of you, which is that both of the Democrats who are running, because they have demonstrated an understanding and a commitment to building on the progress that we've made thus far, would be far better presidents than anybody that's been put up on the Republican side."