WASHINGTON - Pat Toomey is up next.

Republicans won control of the Senate Tuesday, but as Democrats look to quickly reclaim the majority, they see the Pennsylvania Republican as one of the country's most inviting targets, setting up what could be one of the hottest Senate races of 2016.

Democrats are eager for a shot at Toomey after seeing him beat Joe Sestak by just two percentage points in 2010, even with the tea party wave behind him. They expect a more favorable playing field this time around, and (they hope) help from star power in the presidential race.

Toomey "should be a stronger candidate in '16 than he was in '10 -- except one problem: Hillary Clinton," said former Democratic Gov. Ed Rendell. "I would love to be a Democrat running against an incumbent Republican senator in 2016."

Much as Republicans ousted red-state Democrats Tuesday, Democrats plan to go after the many blue-state Republicans defending seats in 2016, knowing that presidential campaigns bring wins in places like Pennsylvania.

Toomey supporters, like the Keystone State GOP guru Bob Asher, say the senator is "extremely well-positioned" to win anyway, given his record and acumen. But even the senators' admirers expect an onslaught.

"It's a challenging year for any Republican, particularly in Pennsylvania," said Alan Novak, a former Republican state chairman from Chester County.

Presidential races, he said, energize Democrats in places like Philadelphia and its surrounding suburbs.

Sestak, a former admiral and Delaware County congressman, is already traveling the state and raising money. He had $1.3 million in his last campaign report.

Other Democrats who have been rumored as options include Attorney General Kathleen Kane (though her stock has fallen), Montgomery County Commissioner Josh Shapiro, Allegheny County Executive Rich Fitzgerald and Katie McGinty, the former state environmental secretary who ran for governor.

Toomey has a head start -- he's an incumbent with $5.4 million in campaign funds -- and he'll have a chance to burnish his resume in a GOP-held Senate. On Wednesday he called it "a big opportunity for constructive progress."

He plans to push a "pro-growth" agenda that includes approval of the Keystone XL Pipeline, rolling back regulations on banks and repealing a tax on medical device makers.

But there's also the threat that ideas pushed by hard-line colleagues like Sen. Ted Cruz (R., Tex.) complicate Toomey's political life and attempts to appeal to the moderates who could swing Pennsylvania races in 2016.

"That's more than two years away," Toomey said in a recent interview. "For now, for me, this is all about being productive."

At the center of the race will be a debate over who Toomey is: a principled but pragmatic fiscal conservative willing to compromise -- as he famously did on a bill to expand background checks to cover more gun purchases -- or a right-wing idealogue hiding behind a mild demeanor?

Both parties will put their thumbs on the scale, along with stacks of cash.

But some of Democrats' big-money players may help Toomey.

Several prominent Philadelphia Democrats have aided him, from labor -- he got $10,000 from the electrical workers' local led by John "Johnny Doc" Dougherty -- up to the executive suite.

Comcast executive vice president David L. Cohen last year hosted a fund-raiser for Toomey at his home, a place President Obama visited so much he once joked that the only thing he hadn't done there was join a Passover seder.

One co-host, veteran Democratic fund-raiser Alan Kessler, told of getting "raised eyebrows and nasty e-mails" from some fellow Democrats. But Kessler said Toomey promised him in 2010 that he would try to reach across the aisle. Kessler aided Toomey that year, too, and said the senator delivered.

"Has he been where I like him to be most of the time? Of course not," said Kessler, an attorney and former vice chair of Democrats' national finance team. "Has he stood by his word in terms of dealing with Democrats when he could? The answer to that is he upheld his commitment to me."

Philanthropist H. F. "Gerry" Lenfest, publisher of The Inquirer, is another Toomey donor.

Of course, incumbents of all stripes, including the just-defeated Gov. Corbett, gain wide-ranging support - they're the ones with influence. Kessler said his clients aren't just Democrats or Republicans. "You need friends on both sides of the aisle," he said.

Toomey could also get help from high-profile advocates of tougher gun laws. Groups led by former New York Mayor Michael Bloomberg and ex-Arizona Congresswoman Gabby Giffords, a Democrat wounded in a 2011 shooting, lauded the Republican for courage after he sponsored the background check bill, and they have promised to back up their allies.

This year they put ads on television and workers on the ground to help U.S. Rep. Mike Fitzpatrick (R., Pa.), of Bucks County, among others.

"People who stand for common sense gun regulations are people that we will support," said John Feinblatt, president of Bloomberg's Everytown for Gun Safety.

With national attention pouring in, both sides should have plenty of money. It's the bridge-building symbolism that might mean more in this race.

Toomey, after all, ran as a true conservative who pushed the late-Sen. Arlen Specter out of the GOP.

But while Democrats thought he'd be easy to paint him as a bomb-throwing right-winger, Toomey threw political curve balls instead.

He has struck a delicate balance in his approach and votes.

"He comes across very measured," said Larry Ceisler, a Democratic analyst. "That's going to make it very hard for the media consultants to turn him into a person you hate."

Unlike former Sen. Rick Santorum (R., Pa.) -- who became known as an unyielding culture warrior -- Toomey, an ex-banker with a business-like demeanor, has focused on fiscal matters, staying firmly conservative there while moving toward the center on several big social issues.

The background check bill, written with Sen. Joe Manchin (D., W.Va.) after the Sandy Hook school shooting, landed the two on the front page of the New York Times and in a Saturday Night Live parody before it fell short.

Toomey was also one of a handful of Republicans to vote for bills to protect gays and lesbians from workplace discrimination and the Violence Against Women Act. He supported the 2012 deal to avert the so-called "fiscal cliff."

"He's positioned himself well to be perceived as somebody who can find a way to get to 'yes,'" said Novak. "Pat's not an angry guy."

But Democrats say a full look at Toomey's record tells another story.

He was one of just 18 senators to vote against the deal to end last year's government shutdown, saying he opposed the new borrowing it allowed.

He argued against shuttering the government, but his vote still put him in the same column as Cruz, the stand-off's champion.

Democrats will also point to votes against raising the minimum wage and a bill on equal pay for women and to his opposition to same-sex marriage.

And they'll highlight his leadership of the fiscally conservative Club for Growth, which agitates against compromise and aggressively targets moderate "Republicans In Name Only."

In 2008 Toomey wrote a Wall Street Journal op-ed headlined, "In Defense of RINO Hunting."

"I don't think his brand of extremism plays well in Pennsylvania," said Justin Barasky, a spokesman for Democrats' national Senate campaign arm.

Democrats have dominated Pennsylvania's statewide races since Toomey and Corbett won in 2010.

Obama, Sen. Bob Casey and Kane won in 2012.

Tom Wolf clobbered Corbett Tuesday and Democrats have won the commonwealth in the last six presidential contests.

If that streak continues, Toomey will have to somehow convince voters who back Clinton (or another Democratic nominee) to change columns for the Senate race.

And if Republicans choose a far-right presidential nominee, Ceisler said, their ticket "is going to have a lot of problems in Pennsylvania."

Of course, much can change by 2016.

Toomey, who believes in term limits, has said this will very likely be his last run for Senate.

He'll have a fight on his hands to go out a winner.

@JonathanTamari