Forget the PennDot crews. Over the next two weeks, Pennsylvania needs to brace for roving motorcades of aspiring presidents: black SUVs, panel vans, and press buses.

Politics also will clog TVs and Web browsers with candidate ads, and mailboxes will be stuffed with slick appeals. Expect telephone calls, from prerecorded famous people and live volunteers alike, especially if you regularly vote in Democratic or Republican primaries.

"Polls show the races in both parties narrowing," said Terry Madonna, pollster and professor at Franklin and Marshall College in Lancaster. "Pennsylvania visits and ads are going to pick up in intensity."

It's already underway.

On Saturday, Hillary Clinton's campaign launched a 30-second TV ad statewide that highlights her preparation as first lady, senator, and secretary of state. "The presidency is the toughest job in the world, and she's the one who'll make a real difference for you," the spot concludes.

Backers of Ohio Gov. John Kasich fired the first salvo Friday in the coming Republican onslaught, a 30-second blast at rivals Ted Cruz and Donald Trump called "Crazy." With Patsy Cline's famous song as the score, the spot says Cruz's father told him he was "anointed by God" for high office, and highlights Trump's proposal to register Muslims and refusal to rule out using nuclear weapons in Europe.

"That the best we can do? No, it's not. John Kasich. Stable. Presidential," says the ad. Its sponsor, a super PAC called New Day for America, vowed to spend more than $1 million to air it in New York and Pennsylvania.

The ground war, too, has begun. Clinton and Democratic rival Bernie Sanders spoke to the state AFL-CIO in Philadelphia last week. Clinton met in Kensington with young men in a job-skills program, while Sanders spoke to 10,000 at a Temple University rally.

With both parties' nominations not yet settled, all of the candidates are planning to target Pennsylvania's April 26 primary. The state is the richest prize in the "Acela primary," with Rhode Island, Connecticut, Delaware, and Maryland also voting that day.

"I don't think the campaigns will vary much from their established messages here," Madonna said. "It may look a bit like Michigan and Ohio with the emphasis on manufacturing and trade. In the suburbs, you'll hear more about gender equality."

For now, the candidates are dividing their travel time largely between New York, which votes April 19, and Pennsylvania.

Republicans seem headed to a contested convention, with the odds growing longer against one of the remaining candidates reaching a majority, 1,237 delegates, by the end of primary voting June 7.

Trump's romp to the front of the pack has caused turmoil in the GOP, and the goal for some in its center-right mainstream is to stop the rash billionaire. His trajectory has slowed, with a landslide loss in Wisconsin last week.

Over the weekend, Trump was off the trail, working to retool his campaign from one based mostly on his instincts to a broader organization under experienced advisers. He hopes to come roaring back in New York, his home, and Pennsylvania.

Sanders has won eight of the last nine states - including Wyoming's Democratic caucuses Saturday - but he has not closed Clinton's lead in delegates because of party rules that divide them proportionally. He needs to soar in the two delegate-rich states.

"If he can't steal a big state from Hillary and change the conversation about this race, he's sunk," said Philadelphia-based Democratic strategist Mark Nevins, who called New York a "benchmark" for Sanders. It is Clinton's adopted home state, which she represented in the Senate. And Sanders grew up in Brooklyn, his Flatbush accent still strong after 50 years in Vermont.

Sanders has vowed to fight to the end, and he has the money to do it, having outraised Clinton thanks to millions of small-dollar donors.

Nevins worked on Clinton's 2008 Pennsylvania primary campaign, an epic battle against then-Sen. Barack Obama, but his analysis of the race is widely shared among unaffiliated Democratic strategists and outside analysts.

The Sanders team is mobilizing all hands for action in Pennsylvania. On Saturday, the campaign held "Bernie Camps" to train volunteers for canvassing and organizing.

"We'll have a very robust ground operation," Ryan Hughes, state director for the Sanders campaign, said. He counts 23 field offices.

"We're going to knock on a lot of doors, and we think that's what's going to make us competitive at the end of the day," Hughes said.

Clinton, whose father grew up in Scranton, has deep personal and political ties to the state.

She's got the backing of party bigwigs, including former Gov. Ed Rendell, Mayor Kenney, and Sen. Bob Casey, as well as influential ward leaders such as former City Councilwoman Marian Tasco, who introduced Bill Clinton at a rally Thursday in Northwest Philadelphia, a high-vote African American area.

But Clinton also had the party establishment in Michigan, where she played the Flint water-crisis issue like a Stradivarius - and still lost there to Sanders.

Unlike Michigan, Pennsylvania has a closed primary, open only to voters registered with a party. Independents can't flock to vote Democratic as they did for Sanders in the Wolverine State.

Hughes said that the closed primary is "even more of a challenge" for Sanders than overcoming Clinton's strong support from black voters and those over 65.

A test for Trump

On the Republican side, Trump, too, usually fares better in primaries that welcome independents. So the Keystone State's closed primary is a test.

He's got the state GOP establishment against him but is backed by two upstate members of Congress - plus Montgomery County Commissioner Joe Gale, the first elected official in the state to endorse him.

Gale, 27, calls his election last year over the opposition of the county GOP a "mirror" of Trump's campaign. "I'm the proof in the pudding" that Trump can do well in Pennsylvania, Gale said.

"He's never been embraced by the establishment, and the fact that they don't want him is his strength," Gale said of Trump. "He's not beholden."

Trump is leading in the latest Pennsylvania polls, but only by single digits.

Kasich, who grew up near Pittsburgh, has many Republican stars in his corner, such as former Gov. Tom Ridge and national committeeman Bob Asher. And his backers point to national polls showing Kasich - a relative moderate compared with Trump or Cruz - as the best performer against either Democrat in November.

"We see Pennsylvania as a real opportunity," said former Rep. Bob Walker, Kasich's chief strategist in the state. "He's from the west, and a natural candidate for the Philadelphia suburban vote."

If Kasich is a natural for those moderate-minded suburbanites, Cruz may be a natural for central and northern Pennsylvania, analysts say. The Texas senator's base is evangelical Christians and other social conservatives - though they are less numerous here than in earlier voting states.

Cruz also has become a rallying point for anti-Trump Republicans of other stripes and is riding high after his Wisconsin win.

"There's a plausible scenario for all three candidates," said Charlie Gerow, a veteran GOP strategist in Harrisburg who has worked on several presidential campaigns.

"This thing could go anywhere," he said.

tfitzgerald@phillynews.com

215-854-2718@tomfitzgerald

www.philly.com/bigtent