SO NOW we have renewed focus on gun laws, a flurry of activity in Congress and national attention on Pat Toomey.

Oh, and with Toomey in a serious re-election challenge, charges from opponent Katie McGinty that Toomey's on the wrong side of guns and/or pandering to make it look as if he's on the right side of guns - whatever that might be.

Anyway, GOP Sen. Toomey's in the eye of the storm as the Senate's expected to take up gun measures he doesn't like and Democrat McGinty's expected to lambaste him no matter what.

It's the politics of guns. Reaction to mass shootings in Orlando on June 12 like there was to San Bernardino last year or in Newtown in 2012, etc., etc.

It's what we do. There's always a post-event commotion.

But if history's a guide, this will pass as others did with little if any substantive change. It's a uniquely American situation. Other countries with mass shootings (Germany, Australia, Great Britain) enact stricter gun laws.

After mass shootings here, gun sales go up, Congress continues to ban research dollars into gun violence as a public health issue and politicians seek to grab political gain from the suffering of others.

So expect noise; at least for a while.

But, for three reasons, guns won't topple Toomey.

First, concentration on guns will fade. Always does. And who knows what event or issue drives the race two months from now or in its final weeks or days?

Second, Toomey's inoculated: his bipartisan efforts since 2013 to expand background checks gained wide recognition, including from the likes of Vice President Biden, putting Toomey in a good place for his state.

Although Pennsylvania's pro-gun, 88 percent of its registered voters favor federal background checks for purchases, including at gun shows and online, according to findings of a January Franklin & Marshall College poll.

So Toomey's generally viewed as a common-sense vote on guns.

If you doubt that and don't think Democrats are trying to change it, I'd refer you to last Friday's New York Times report that "some prominent Democrats have told fellow party members not to work with Mr. Toomey."

Third, Toomey's got a bigger problem.

His threat isn't guns. It's a loose cannon: Donald Trump - McGinty's strongest asset.

Toomey tightropes on Trump as other Republicans distance themselves because Toomey needs Trump supporters in order to win in November.

Trump won every county in the state's April GOP primary. He got more than 900,000 votes. Let's say 20 percent to 30 percent of that is hard-core Trump support in November. That's potentially 180,000 to 270,000 votes, including tens of thousands of new GOP voters.

Toomey won his first term in 2010 beating Joe Sestak by 80,000 votes.

Also, the structure of the vote and recent tendencies not to split tickets don't favor Toomey.

There are 936,000 more registered Democrats than Republicans (and 1.08 million independent and other-party voters). And while the state split tickets in past, there's evidence it's part of a national trend of one-party voting, the result of ongoing excessive polarization.

In 2012, for example, a Democrat won every statewide race, president to auditor general. In 2014, Democrat Tom Wolf won the only statewide race. In 2015, Democrats won all five statewide judicial races.

So Toomey's at high-risk. As McGinty continues to tie Toomey to Trump, Toomey needs to find a way to keep some ties, even if few in number and loose in nature.

But the ever-contentious gun issue? When it comes to Toomey, it's trumped.