Rudy Giuliani on Monday accused Kentucky GOP Senate candidate Rand Paul of being part of the "blame America first crowd."

TOP OF THE BALLOT TODAY: A three-way tie in Hawaii; Romney and Obama hit the campaign trail; Dems line up Isakson challenger in Georgia, just in case.

Toss-up in Hawaii

There's essentially a three-way toss-up in the May 22nd Hawaii special election.

The liberal website Daily Kos released a Research 2000 poll over the weekend. It showed Republican Honolulu City Councilman Charles Djou leading the way at 32 percent, while former Rep. Ed Case (D-Hawaii) and state Senate President Colleen Hanabusa (D) were close behind at 29 percent and 28 percent, respectively.

Case got a big boost on Sunday, when the Honolulu Advertiser endorsed him. But unless that endorsement helps him steal support from Djou, it may only cut up the Democratic equation even more.

What’s interesting here is that Case enters the race with significantly better favorable numbers (47 percent positive, 25 percent negative) than Hanabusa (37 percent positive, 31 percent negative). Djou (40 and 27) is somewhere in between.

Romney for Rubio; Barack for Boxer

A couple of big-name Senate candidates are getting some even bigger-name help today, with President Obama raising money for Sen. Barbara Boxer (D-Calif.) and Mitt Romney doing an event with former Florida state House Speaker Marco Rubio (R).

Obama joins Boxer as she finds herself in what is looking to be her most difficult reelection race yet, while Romney is a little on the late side in jumping on the Rubio bandwagon (especially now that it appears Gov. Charlie Crist is considering an independent bid instead of running in the GOP primary).

Still, the high-profile visits would have been nearly unthinkable a year ago, when Boxer’s challenge was still hypothetical and Crist looked like a future GOP presidential candidate.

Isakson challenger emerges

Sen. Johnny Isakson’s (R-Ga.) recent health problems have spurred Democrats to field a challenger in that race, and they got a good one.

State Labor Commissioner Michael Thurmond, who is one of just two Democrats elected to statewide office in the state, is expected to join the race Tuesday.

It’s hard to see the Democrats going after Isakson hard – he showed a 53-26 lead on Thurmond in a recent Daily Kos poll – but his candidacy forces Republicans and Isakson to reevaluate themselves and puts Democrats in a position to take advantage if, for whatever reason, Isakson isn’t able to campaign.

Other updates

-Former health insurance executive Charlie Baker, the party favorite, won an overwhelming victory over former independent candidate Christy Mihos at the Massachusetts Republican Party convention, forcing Mihos from the race to face Gov. Deval Patrick (D).

-Rep. Jane Harman (D-Calif.) survived her own convention scare, defeating activist Marcy Winograd (D) 599-417 and winning her party's endorsement in their primary.

Rep. Stephen Lynch (D-Mass.), himself a former local union president, could be facing a primary challenge from a labor official from the Bay State.

The Boston Globe reported Monday that Mac D'Alessandro, a regional political director for the large service worker's union SEIU, is seriously weighing a run against the sixth term lawmaker, who was the only Massachusetts Democrat to vote against the Democrats' healthcare bill last month.

Here is more from the Globe:

D’Alessandro, who has worked for the Service Employees International Union for nine years, downplayed the role that Lynch’s health care vote played in his decision to jump into the race, saying instead that he wants to bring a different voice to Capitol Hill.

“This is a personal decision for me, as a constituent, as someone who has progressive values,’’ he said. “This isn’t part of me being recruited, no, this is my wanting a stronger voice for the district, for my family and the other families.’’

Asked if he would have voted in favor of Obama’s health care reform bill, he said, “Absolutely.’’

“I’m going to be on the side of consumers and workers, and not on the side of health insurance companies and big banks,’’ he said.

But for now, he said, he is focused on getting on the ballot. “We’ll have more to say once we do that,’’ he said.

State Democratic Party chairman John Walsh welcomed the announcement of a potential new candidate for the state’s Ninth Congressional District, which includes parts of Boston and extends south of the city into Norfolk, Plymouth, and Bristol counties.

“I think it’s a sign of a healthy party that there’s a discussion and a debate,’’ Walsh said.

D'Alessandro has until May 4 to collect the 2,000 signatures necessary to appear on the ballot. Lynch already faces two opponents already, one a Republican and the other an independent.

Some liberal activists have encouraged primary challengers to run against Democrats who voted against the healthcare bill, another sign that the massive $940 billion new law will play a major role in the fall midterm elections.

Walsh told the Globe that the challlenge would be an “uphill fight’’ for D’Alessandro, but said its result is not a foregone conclusion.

Tickets for an exclusive fundraising dinner with the president are $35,200 per couple, split between Boxer and the DNC.

Dino Rossi, a former Washington state senator and two-time gubernatorial candidate, is Cornyn’s favored challenger to Dem Sen. Patty Murray.

The Majority Leader did not signal support for either Florida Gov. Crist or state House Speaker Marco Rubio by name.

The senator said he passed the "litmus test" of being a true conservative over J.D. Hayworth on opposition to earmarks, pork.

Recent polls have shown key parts of the Democratic base are less motivated than their Republican counterparts to vote this cycle but that doesn't worry California Democratic Party Chairman John Burton.

Burton said young people will go to the polls in November with a specific issue in mind -- pot.

Young supporters of President Obama will turnout in order to support the ballot initiative to tax and regulate pot in California, Burton told the San Francisco Chronicle Friday before the state party’s convention kicked off in Los Angeles. 

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Texas Gov. Rick Perry (R) continues to boost his national profile as he denies any plans to run for president.