Hillary Clinton has solid lead over Donald Trump in electoral college

The problem for the Trump camp is that it is unclear about its winning map.

Over the last few days of the race, Donald Trump intends to travel all over the country. He's going to Florida, North Carolina, Nevada, Colorado, Iowa, Michigan, Pennsylvania, New Hampshire and even Minnesota, he said.

It's an impressive travel schedule, but it may reflect the biggest challenge facing him right now: It's still not clear exactly where and how he would win.

Hillary Clinton has a consistent and clear advantage in states worth at least 270 electoral votes, even as the race has undoubtedly tightened over the past few weeks. But even that understates the challenge facing Trump's campaign.

This is not to say that Trump can't win. The polls could be off across the board. But even if he wins Arizona, Iowa, Ohio, Utah, North Carolina, Florida and New Hampshire, he's still short of a victory.

He's not assured to win any of those states, to be clear - although he's a clear favorite in Iowa and Utah at this point. He has trailed in more live interview polls of North Carolina and Florida than he has led, although the national race has tightened since many were taken.

But he would still need to win one of the following states: Pennsylvania, Nevada, Michigan, Wisconsin, Colorado, Virginia or perhaps New Mexico or Minnesota. Of all of these states, the only one where Trump has really been close in the polls is Nevada.

But Nevada is also the state where we know the most about the results because of early voting, and it hasn't brought good news for Trump. Many analysts have concluded that Trump has basically lost the state already. But if Clinton does indeed have a big advantage in Nevada, then his chances start looking very bleak: He's at a disadvantage in the polls of all of the other states that could put him over the top.

What's more, it's not really clear where he has his best chance - something reflected in Trump's unfocused pre-election push.

Pennsylvania seemed like Trump's best option earlier in the year, but he hasn't led a live interview poll there since the summer. The final nonpartisan live interview polls there show Clinton ahead by a comfortable margin of 4 to 6 points.

Michigan could be a more interesting option for Trump. It was the most Democratic of all of these states in the 2012 election, and he hasn't led a poll there all year either. But recent polls have shown a relatively tight race.

Colorado is a notch tougher than any of those states. There was one recent poll that showed a tied race in Colorado, but most have shown Clinton with a lead. Virginia is like Colorado: Neither polls nor demographics seem promising for Trump. Clinton has a big lead in Virginia. Then there are states like Minnesota and New Mexico. The polls have not shown an especially tight race, and Clinton is not campaigning or airing advertisements there. Trump's team has held out some hope of winning, but these states seem especially unlikely to decide the election.

Again, the polls are close enough that the possibility of a victory for Trump is still quite real. But it's just not clear exactly how or where he would break through. It doesn't seem that the Trump campaign knows either.

SENATE CONTROL UP FOR GRABS In a half-dozen states, Democrats, who just two weeks ago were confident they would retake control of the Senate, are now far less certain, and their fates may well be tied to the rancorous presidential race and the downbeat attitude of voters that contest has created.

Many thought Hillary Clinton's once-clear lead in New Hampshire would all but ensure a victory for Hassan over the Senate Republican incumbent, Kelly Ayotte, who won her seat in a 2010 Tea Party-infused election. But this Eastern cornerstone for Democrats is cracking.

Democrats' hopes had risen largely because of Donald Trump's weakness in some states and an overall disorganised Republican effort to rally potential voters. Now, at least four races - in New Hampshire, North Carolina, Indiana and Missouri - are considered dead heats, and Democratic prospects are only slightly better in Pennsylvania, Wisconsin and Nevada.